Monk Customs presents: CSG! The first HPA only gearbox out there. With the split gearbox design doing maintanence on your HPA engine is no longer a hassle, just remove your upper and you are able to service your HPA engine without removing the gearbox from the lower receiver and having to unscrew your grip.

Apart from that its a perfect marriage with the new MFCU that will fit perfectly in CSG gearbox adding ample space to your ESG HPA Grip.