Are you asking about the dropshot mod? Yes.
What is Drop Shotting? When drop-shot is enabled, and you fire your weapon, your soldier will automatically drop to the ground - making it very difficult for your opponent to shoot you, as he is left shooting in the air where you used to be!
What is Jump Shotting? When jump-shot is enabled, and you fire your weapon, your soldier will automatically jump up in the air - throwing your opponent's aim off.
To turn on drop/jump shot, hold the mod switch and then tap the crouch button. Player 3 led will twinkle and then stay lit to let you know a special mode has been activated.
To change drop/jump shot to a different mode, hold the mod switch and hold the crouch button, then count the number of blinks on the Player 3 LED:
Mode 1: Drop shot. Soldier drops automatically when you fire.
Mode 2: Drop shot. Soldier drops automatically when you fire, except if you are scoping.
Mode 3: Jump shot. Soldier jumps automatically when you fire.
Mode 4: Jump shot. Soldier jumps automatically when you fire, except if you are scoping.