Hop-up chamber elements are designed for the typical chambers used in the M4 type carbine replicas and similar. The set includes the plastic made elements of the chamber, such as the knob, clip or the chamber's arm, a set of springs and clipses and a metal barrel clip.

This set allows to repair a damaged hop-up chamber and gives the certainty or the applied parts. The elements consisted in the set can also be used in the other manufacturer's stand-alone hop-up set.