O-ring

An O-ring is an internal part found on all plunger-system blasters.

Details
An O-ring forms a seal in the plunger tube, and in direct plungers, it also forms a seal in the plunger head. The point of the seal is to keep the air in, and push it out the other side, which increases performance. It also forms a better seal than plastic.

Modification
Modification of the O-ring usually means replacing the O-ring with a one with a better seal, O-ring replacements usually have more rubber, or is more sealed overall, which increases performance. Another modification for the O-ring, is re-lubricating the O-ring to form a better seal. Orange Mod Works sells grease to help re-lubricate the O-ring. Caution is advised, as removing the O-ring without care can cause it to snap, as it is fragile under pressure. Thus the O-ring has to be removed slowly, and with care as well.

Additional material, such as electrical tape, can be wrapped around the plunger head under the O-ring to increase its seal. However, this modification is usually done for HAMP-action blasters such as the ThunderBlast or the Demolisher 2-In-1's missile blaster, as the friction from the increased seal may hinder a springer blaster's performance. The friction will also make it harder for the user to work the pump, and the pump may also get stuck at times.