The move is performed by pointing a single finger at the target and charging, or in Drew and the rest of it's users's cases later on touching the index and middle fingers of one hand to the forehead and charging enough energy to attack. When ready, the fingers are extended forward if initialy on forehead, two thin ki beams are unleashed from the fingers. One remains straight while the other coils around the straight beam. The resulting beam is quite powerful, either drilling through its target or exploding if it can't. According to Drew, the beam is capable of killing an opponent four times the user's strength.
Edd was capable of precisely aiming his Special Beam Cannon to the point that he could accurately pierce #10's energy core exactly how he wanted to.
Drew's Special Beam Cannon was once capable of clashing with Zachs Final Flash, an impressive feat considering it's lack of destructive capability in comparison.
In Dark Buu vs the Eds, Ed uses a green version of the technique called Super Special Beam Cannon, which was powerful enough to drill through Dark Buu.