Two stacked upward solid triangles, a fast up or double up arrow button, used for scrolling up or high priority.
U+1F53CUP-POINTING SMALL RED TRIANGLEU+1F53DDOWN-POINTING SMALL RED TRIANGLEU+23ECBLACK DOWN-POINTING DOUBLE TRIANGLEU+23EEBLACK LEFT-POINTING DOUBLE TRIANGLE WITH VERTICAL BARU+23F8DOUBLE VERTICAL BARU+23EABLACK LEFT-POINTING DOUBLE TRIANGLEU+23F9BLACK SQUARE FOR STOPU+25C0BLACK LEFT-POINTING TRIANGLEU+23FABLACK CIRCLE FOR RECORDU+23EFBLACK RIGHT-POINTING TRIANGLE WITH DOUBLE VERTICAL BARU+23CFEJECT SYMBOLU+23EDBLACK RIGHT-POINTING DOUBLE TRIANGLE WITH VERTICAL BAR256 characters in the Miscellaneous Technical Unicode block, from number 236.
U+23EBBLACK UP-POINTING DOUBLE TRIANGLEU+23ECBLACK DOWN-POINTING DOUBLE TRIANGLEU+23EDBLACK RIGHT-POINTING DOUBLE TRIANGLE WITH VERTICAL BARU+23EEBLACK LEFT-POINTING DOUBLE TRIANGLE WITH VERTICAL BARU+23EFBLACK RIGHT-POINTING TRIANGLE WITH DOUBLE VERTICAL BARU+23F0ALARM CLOCKU+23F1STOPWATCHU+23F2TIMER CLOCKU+23F3HOURGLASS WITH FLOWING SANDU+23F4BLACK MEDIUM LEFT-POINTING TRIANGLEU+23F5BLACK MEDIUM RIGHT-POINTING TRIANGLEU+23F6BLACK MEDIUM UP-POINTING TRIANGLEU+23F7BLACK MEDIUM DOWN-POINTING TRIANGLEU+23F8DOUBLE VERTICAL BARU+23F9BLACK SQUARE FOR STOPU+23FABLACK CIRCLE FOR RECORDU+23FBPOWER SYMBOLU+23FCPOWER ON-OFF SYMBOLU+23FDPOWER ON SYMBOLU+23FEPOWER SLEEP SYMBOLU+23FFOBSERVER EYE SYMBOL