I thought I would do a quick post with my thoughts on the Prowin Hopup unit, Prometheus purple bucking  & Firefly Namazu flat hop nub, hop up set up which I have just installed on both my M4 (both G&G).   I found this setup through the Amped Airsoft YouTube channel, where they have a video detailing the products and how to fit them.  I will put a link to the video at the bottom.   The quality of all these products is great.  The Prowin seems very solid and has a very