Angel Custom CNC Aluminum Blowback Housing for APS Shark, ISSC M22, SAI BLU, Lonewolf, & Compatible Airsoft Gas Blowback Pistols

"This thing is a complete drop in for the WE G17. The reason why past reviewers say the unit catches on their trigger when they rack the slide is because they didn't remove the gummy protective sticker on the top of the BBU. Once removed, it sits flush in the slide. Note, the air seal with the stock Blowback Nozzle is superb. For those concerned about the weight, this thing is roughly 25 to 30g. Definitely heavier than Guarder's 20g BBU (Which isn't exactly a drop in for WE G17). The red coating wears off fairly quick in the contact areas between the trigger and the BBU. Overall a great BBU that's simple to install and aesthetically pleasing.

"I'll start off by saying that I love this housing because it can result in a higher cycle rate and adds to the overall look of the gun.
As someone who works as a tech at a field I feel the performance is great and I had no problems with the angle of engagement of the nozzle or either of the slides I installed it into which were both plastic and metal and TM/WE. With that said, I finally wore the housing out after ~1 year of gameplay while playing every week almost without fail. Even then the only area that was severely worn was the section where the Trigger bar makes contact with the housing. In total I was very impressed with the performance of the housing and I plan on ordering another one soon.

"This BBU will snag on your hammer assembly, and is NOT a drop in kit. Unless you can sand down a certain part of it you won't be able to use it out of the box. Other than this problem the build quality is amazing, and is much lighter than the OEM BBU.