Product Description
The Hopup Chamber M4A unit is built with an aluminum Rotary Dial Knob for fine hopup adjustments, the precision Hopup Lever and 4mm Bucking Nubs (6mm Bucking Nubs are optional) to perform best with R-Hop and Standard-Hop to keep the BB shooting accurately and consistently on every single shot.The Hopup Chamber M4A unit is designed to accept 21.00mm to 21.25mm nozzle length, and fully compatible with most aftermarket soft and hard rubber buckings without losing FPS or dropping BB during use.