Vipertech O-Rings
16mm bolt carrier
Rear nozzle piston - 2mm X 11mm
Front nozzle piston - 2mm X 12mm
Nozzle return spring assembly - 4mm X 1mm
18mm bolt carrier
Rear nozzle piston - 2mm X 13mm
Front nozzle piston - 2mm X 14mm
Nozzle return spring assembly - 4mm X 1mm
Z parts bolt carrier
Nozzle piston - 2mm X 15mm
Nozzle return spring assembly - 4mm X 1mm
VFC UMP O-Rings
Nozzle piston - 2mm X 14mm
Nozzle return spring assembly - 1.5mm X 5mm
Magazine output valve - 1mm X 6mm and 1mm X 7mm
Magazine Input valve o ring - 1.5mm X 4mm