HAO's latest design : "Charging handle recoil system" is now ready to ship, 
In this package you will receive the fully "recoil" PTW charging handle in set ;
Charging Handle (AR15/HK416)
Gastube  (Gastube/Direct Gastube)
We revised the design of the charging handle to make it to be able to perform the act of cocking the charging handle.This function brings some fun to the PTW platform but please be noted that this charging handle doesn't allow you to pull out the PTW cylinder like the standard AR charging handle.

Here're the combination: 
HAO's Charging handle recoil Full system for PTW M4(A)-BLACK
HAO's Charging handle recoil Full system for PTW HK416(B)-BLACK
HAO's Charging handle recoil Full system for PTW M4(C)-DDC
HAO's Charging handle recoil Full system for PTW HK416(D)-DDC



Clip:
https://www.youtube.com/watch?v=InZCum9ejv8