Long right arrow stacked above a long left arrow, like a reversible reaction or equilibrium symbol.
U+1F8D1LONG RIGHTWARDS HARPOON OVER LONG LEFTWARDS HARPOONU+1F8D2LONG RIGHTWARDS HARPOON ABOVE SHORT LEFTWARDS HARPOONU+1F8D3SHORT RIGHTWARDS HARPOON ABOVE LONG LEFTWARDS HARPOONU+1F8D4LONG LEFTWARDS HARPOON ABOVE SHORT RIGHTWARDS HARPOONU+1F8D5SHORT LEFTWARDS HARPOON ABOVE LONG RIGHTWARDS HARPOONU+1F8D6LONG RIGHTWARDS ARROW THROUGH XU+1F8D7LONG RIGHTWARDS ARROW WITH DOUBLE SLASHU+1F8D8LONG LEFT RIGHT ARROW WITH DEPENDENT LOBEU+1F8C1RIGHTWARDS ARROW FROM DOWNWARDS ARROWU+1F8C0LEFTWARDS ARROW FROM DOWNWARDS ARROWU+1F8BBSOUTH WEST ARROW FROM BARU+1F8BASOUTH EAST ARROW FROM BAR171 characters in the Supplemental Arrows-C Unicode block.
U+1F800LEFTWARDS ARROW WITH SMALL TRIANGLE ARROWHEADU+1F801UPWARDS ARROW WITH SMALL TRIANGLE ARROWHEADU+1F802RIGHTWARDS ARROW WITH SMALL TRIANGLE ARROWHEADU+1F803DOWNWARDS ARROW WITH SMALL TRIANGLE ARROWHEADU+1F804LEFTWARDS ARROW WITH MEDIUM TRIANGLE ARROWHEADU+1F805UPWARDS ARROW WITH MEDIUM TRIANGLE ARROWHEADU+1F806RIGHTWARDS ARROW WITH MEDIUM TRIANGLE ARROWHEADU+1F807DOWNWARDS ARROW WITH MEDIUM TRIANGLE ARROWHEADU+1F808LEFTWARDS ARROW WITH LARGE TRIANGLE ARROWHEADU+1F809UPWARDS ARROW WITH LARGE TRIANGLE ARROWHEADU+1F80ARIGHTWARDS ARROW WITH LARGE TRIANGLE ARROWHEADU+1F80BDOWNWARDS ARROW WITH LARGE TRIANGLE ARROWHEADU+1F810LEFTWARDS ARROW WITH SMALL EQUILATERAL ARROWHEADU+1F811UPWARDS ARROW WITH SMALL EQUILATERAL ARROWHEADU+1F812RIGHTWARDS ARROW WITH SMALL EQUILATERAL ARROWHEADU+1F813DOWNWARDS ARROW WITH SMALL EQUILATERAL ARROWHEADU+1F814LEFTWARDS ARROW WITH EQUILATERAL ARROWHEADU+1F815UPWARDS ARROW WITH EQUILATERAL ARROWHEADU+1F816RIGHTWARDS ARROW WITH EQUILATERAL ARROWHEADU+1F817DOWNWARDS ARROW WITH EQUILATERAL ARROWHEADU+1F818HEAVY LEFTWARDS ARROW WITH EQUILATERAL ARROWHEADU+1F819HEAVY UPWARDS ARROW WITH EQUILATERAL ARROWHEADU+1F81AHEAVY RIGHTWARDS ARROW WITH EQUILATERAL ARROWHEADU+1F81BHEAVY DOWNWARDS ARROW WITH EQUILATERAL ARROWHEADU+1F81CHEAVY LEFTWARDS ARROW WITH LARGE EQUILATERAL ARROWHEADU+1F81DHEAVY UPWARDS ARROW WITH LARGE EQUILATERAL ARROWHEADU+1F81EHEAVY RIGHTWARDS ARROW WITH LARGE EQUILATERAL ARROWHEADU+1F81FHEAVY DOWNWARDS ARROW WITH LARGE EQUILATERAL ARROWHEADU+1F820LEFTWARDS TRIANGLE-HEADED ARROW WITH NARROW SHAFTU+1F821UPWARDS TRIANGLE-HEADED ARROW WITH NARROW SHAFTU+1F822RIGHTWARDS TRIANGLE-HEADED ARROW WITH NARROW SHAFTU+1F823DOWNWARDS TRIANGLE-HEADED ARROW WITH NARROW SHAFTU+1F824LEFTWARDS TRIANGLE-HEADED ARROW WITH MEDIUM SHAFTU+1F825UPWARDS TRIANGLE-HEADED ARROW WITH MEDIUM SHAFTU+1F826RIGHTWARDS TRIANGLE-HEADED ARROW WITH MEDIUM SHAFTU+1F827DOWNWARDS TRIANGLE-HEADED ARROW WITH MEDIUM SHAFTU+1F828LEFTWARDS TRIANGLE-HEADED ARROW WITH BOLD SHAFTU+1F829UPWARDS TRIANGLE-HEADED ARROW WITH BOLD SHAFTU+1F82ARIGHTWARDS TRIANGLE-HEADED ARROW WITH BOLD SHAFTU+1F82BDOWNWARDS TRIANGLE-HEADED ARROW WITH BOLD SHAFTU+1F82CLEFTWARDS TRIANGLE-HEADED ARROW WITH HEAVY SHAFTU+1F82DUPWARDS TRIANGLE-HEADED ARROW WITH HEAVY SHAFTU+1F82ERIGHTWARDS TRIANGLE-HEADED ARROW WITH HEAVY SHAFTU+1F82FDOWNWARDS TRIANGLE-HEADED ARROW WITH HEAVY SHAFTU+1F830LEFTWARDS TRIANGLE-HEADED ARROW WITH VERY HEAVY SHAFTU+1F831UPWARDS TRIANGLE-HEADED ARROW WITH VERY HEAVY SHAFTU+1F832RIGHTWARDS TRIANGLE-HEADED ARROW WITH VERY HEAVY SHAFTU+1F833DOWNWARDS TRIANGLE-HEADED ARROW WITH VERY HEAVY SHAFTU+1F834LEFTWARDS FINGER-POST ARROWU+1F835UPWARDS FINGER-POST ARROWU+1F836RIGHTWARDS FINGER-POST ARROWU+1F837DOWNWARDS FINGER-POST ARROWU+1F838LEFTWARDS SQUARED ARROWU+1F839UPWARDS SQUARED ARROWU+1F83ARIGHTWARDS SQUARED ARROWU+1F83BDOWNWARDS SQUARED ARROWU+1F83CLEFTWARDS COMPRESSED ARROWU+1F83DUPWARDS COMPRESSED ARROWU+1F83ERIGHTWARDS COMPRESSED ARROWU+1F83FDOWNWARDS COMPRESSED ARROWU+1F840LEFTWARDS HEAVY COMPRESSED ARROWU+1F841UPWARDS HEAVY COMPRESSED ARROWU+1F842RIGHTWARDS HEAVY COMPRESSED ARROWU+1F843DOWNWARDS HEAVY COMPRESSED ARROWU+1F844LEFTWARDS HEAVY ARROWU+1F845UPWARDS HEAVY ARROWU+1F846RIGHTWARDS HEAVY ARROWU+1F847DOWNWARDS HEAVY ARROWU+1F850LEFTWARDS SANS-SERIF ARROWU+1F851UPWARDS SANS-SERIF ARROWU+1F852RIGHTWARDS SANS-SERIF ARROWU+1F853DOWNWARDS SANS-SERIF ARROWU+1F854NORTH WEST SANS-SERIF ARROWU+1F855NORTH EAST SANS-SERIF ARROWU+1F856SOUTH EAST SANS-SERIF ARROWU+1F857SOUTH WEST SANS-SERIF ARROWU+1F858LEFT RIGHT SANS-SERIF ARROWU+1F859UP DOWN SANS-SERIF ARROWU+1F860WIDE-HEADED LEFTWARDS LIGHT BARB ARROWU+1F861WIDE-HEADED UPWARDS LIGHT BARB ARROWU+1F862WIDE-HEADED RIGHTWARDS LIGHT BARB ARROWU+1F863WIDE-HEADED DOWNWARDS LIGHT BARB ARROWU+1F864WIDE-HEADED NORTH WEST LIGHT BARB ARROWU+1F865WIDE-HEADED NORTH EAST LIGHT BARB ARROWU+1F866WIDE-HEADED SOUTH EAST LIGHT BARB ARROWU+1F867WIDE-HEADED SOUTH WEST LIGHT BARB ARROWU+1F868WIDE-HEADED LEFTWARDS BARB ARROWU+1F869WIDE-HEADED UPWARDS BARB ARROWU+1F86AWIDE-HEADED RIGHTWARDS BARB ARROWU+1F86BWIDE-HEADED DOWNWARDS BARB ARROWU+1F86CWIDE-HEADED NORTH WEST BARB ARROWU+1F86DWIDE-HEADED NORTH EAST BARB ARROWU+1F86EWIDE-HEADED SOUTH EAST BARB ARROWU+1F86FWIDE-HEADED SOUTH WEST BARB ARROWU+1F870WIDE-HEADED LEFTWARDS MEDIUM BARB ARROWU+1F871WIDE-HEADED UPWARDS MEDIUM BARB ARROWU+1F872WIDE-HEADED RIGHTWARDS MEDIUM BARB ARROWU+1F873WIDE-HEADED DOWNWARDS MEDIUM BARB ARROWU+1F874WIDE-HEADED NORTH WEST MEDIUM BARB ARROWU+1F875WIDE-HEADED NORTH EAST MEDIUM BARB ARROWU+1F876WIDE-HEADED SOUTH EAST MEDIUM BARB ARROWU+1F877WIDE-HEADED SOUTH WEST MEDIUM BARB ARROWU+1F878WIDE-HEADED LEFTWARDS HEAVY BARB ARROWU+1F879WIDE-HEADED UPWARDS HEAVY BARB ARROWU+1F87AWIDE-HEADED RIGHTWARDS HEAVY BARB ARROWU+1F87BWIDE-HEADED DOWNWARDS HEAVY BARB ARROWU+1F87CWIDE-HEADED NORTH WEST HEAVY BARB ARROWU+1F87DWIDE-HEADED NORTH EAST HEAVY BARB ARROWU+1F87EWIDE-HEADED SOUTH EAST HEAVY BARB ARROWU+1F87FWIDE-HEADED SOUTH WEST HEAVY BARB ARROWU+1F880WIDE-HEADED LEFTWARDS VERY HEAVY BARB ARROWU+1F881WIDE-HEADED UPWARDS VERY HEAVY BARB ARROWU+1F882WIDE-HEADED RIGHTWARDS VERY HEAVY BARB ARROWU+1F883WIDE-HEADED DOWNWARDS VERY HEAVY BARB ARROWU+1F884WIDE-HEADED NORTH WEST VERY HEAVY BARB ARROWU+1F885WIDE-HEADED NORTH EAST VERY HEAVY BARB ARROWU+1F886WIDE-HEADED SOUTH EAST VERY HEAVY BARB ARROWU+1F887WIDE-HEADED SOUTH WEST VERY HEAVY BARB ARROWU+1F890LEFTWARDS TRIANGLE ARROWHEADU+1F891UPWARDS TRIANGLE ARROWHEADU+1F892RIGHTWARDS TRIANGLE ARROWHEADU+1F893DOWNWARDS TRIANGLE ARROWHEADU+1F894LEFTWARDS WHITE ARROW WITHIN TRIANGLE ARROWHEADU+1F895UPWARDS WHITE ARROW WITHIN TRIANGLE ARROWHEADU+1F896RIGHTWARDS WHITE ARROW WITHIN TRIANGLE ARROWHEADU+1F897DOWNWARDS WHITE ARROW WITHIN TRIANGLE ARROWHEADU+1F898LEFTWARDS ARROW WITH NOTCHED TAILU+1F899UPWARDS ARROW WITH NOTCHED TAILU+1F89ARIGHTWARDS ARROW WITH NOTCHED TAILU+1F89BDOWNWARDS ARROW WITH NOTCHED TAILU+1F89CHEAVY ARROW SHAFT WIDTH ONEU+1F89DHEAVY ARROW SHAFT WIDTH TWO THIRDSU+1F89EHEAVY ARROW SHAFT WIDTH ONE HALFU+1F89FHEAVY ARROW SHAFT WIDTH ONE THIRDU+1F8A0LEFTWARDS BOTTOM-SHADED WHITE ARROWU+1F8A1RIGHTWARDS BOTTOM SHADED WHITE ARROWU+1F8A2LEFTWARDS TOP SHADED WHITE ARROWU+1F8A3RIGHTWARDS TOP SHADED WHITE ARROWU+1F8A4LEFTWARDS LEFT-SHADED WHITE ARROWU+1F8A5RIGHTWARDS RIGHT-SHADED WHITE ARROWU+1F8A6LEFTWARDS RIGHT-SHADED WHITE ARROWU+1F8A7RIGHTWARDS LEFT-SHADED WHITE ARROWU+1F8A8LEFTWARDS BACK-TILTED SHADOWED WHITE ARROWU+1F8A9RIGHTWARDS BACK-TILTED SHADOWED WHITE ARROWU+1F8AALEFTWARDS FRONT-TILTED SHADOWED WHITE ARROWU+1F8ABRIGHTWARDS FRONT-TILTED SHADOWED WHITE ARROWU+1F8ACWHITE ARROW SHAFT WIDTH ONEU+1F8ADWHITE ARROW SHAFT WIDTH TWO THIRDSU+1F8B0ARROW POINTING UPWARDS THEN NORTH WESTU+1F8B1ARROW POINTING RIGHTWARDS THEN CURVING SOUTH WESTU+1F8B2RIGHTWARDS ARROW WITH LOWER HOOKU+1F8B3DOWNWARDS BLACK ARROW TO BARU+1F8B4NEGATIVE SQUARED LEFTWARDS ARROWU+1F8B5NEGATIVE SQUARED UPWARDS ARROWU+1F8B6NEGATIVE SQUARED RIGHTWARDS ARROWU+1F8B7NEGATIVE SQUARED DOWNWARDS ARROWU+1F8B8NORTH WEST ARROW FROM BARU+1F8B9NORTH EAST ARROW FROM BARU+1F8BASOUTH EAST ARROW FROM BARU+1F8BBSOUTH WEST ARROW FROM BARU+1F8C0LEFTWARDS ARROW FROM DOWNWARDS ARROWU+1F8C1RIGHTWARDS ARROW FROM DOWNWARDS ARROWU+1F8D0LONG RIGHTWARDS ARROW OVER LONG LEFTWARDS ARROWU+1F8D1LONG RIGHTWARDS HARPOON OVER LONG LEFTWARDS HARPOONU+1F8D2LONG RIGHTWARDS HARPOON ABOVE SHORT LEFTWARDS HARPOONU+1F8D3SHORT RIGHTWARDS HARPOON ABOVE LONG LEFTWARDS HARPOONU+1F8D4LONG LEFTWARDS HARPOON ABOVE SHORT RIGHTWARDS HARPOONU+1F8D5SHORT LEFTWARDS HARPOON ABOVE LONG RIGHTWARDS HARPOONU+1F8D6LONG RIGHTWARDS ARROW THROUGH XU+1F8D7LONG RIGHTWARDS ARROW WITH DOUBLE SLASHU+1F8D8LONG LEFT RIGHT ARROW WITH DEPENDENT LOBE