APS One-Piece Metal Hopup Unit for M4 M16

The APS Metal one piece hopup system comes complete with all the little parts assembled and is compatible with all major M4 M16 series platform full metal AEG. 

Compatibility: For APS, Tokyo Marui, Matrix, Classic Army, JG, Dboy, SRC, CYMA, VFC, G&P and other compatible M4 / M16 Series Airsoft AEG Gearboxes
Material: Metal Alloy