Madbull Ultimate 3-in-1 Hop Up Chamber Unit with LED Module

1. LED Tracer Unit (Optional and Included)
2. Chamber Lock (Prevents BBs from falling out when you eject magazine)
3. Easy adjustment using new design dial for more stable hop-up

This set also includes a free MADBULL blue 60 degree SHARK hop-up bucking rubber.
Note that the chamber lock function works via an O-ring in the BB feed tube that goes up to the firing chamber. The O-ring prevents BB's from falling out of the gun when you pull the magazine out, which is normal in a Marui type gearbox. If you find this causes any problems for you, or you prefer that the 3-4 BB's in the feed tube fall out of the gun during reloads, you can simply remove this O-ring to disable the chamber lock function.

New hop-up adjustment dial stays in place and won't shift from vibration during full-auto firing, giving you more reliable and consistent hop-up than in traditional guns with slide-type hop-up adjustment lever.

And if you need one more reason to get this hop-up unit, Madbull tested this hop-up unit on the Echo1 M4 and got a 5% increase in power due to a better air-seal. So you get 4 benefits in one unit! Need we say more?