Made for a 40 mm external diameter, 36 mm internal diameter pipe build of an E11, or a Sterling replica. You'll still need the bolts for the two holes on each side. They're cheap and available at any decent hardware store. 3D printing them just doesn't look as good with the printer I have access to. This part is based on reference material from the Blaster Builders Club and reference pics from other sources.

The level with the two screw holes should be flush with the barrel. The bolt holes should be horizontal with the concentric ring out towards the lower right side when you look at the blaster from the front. I'm hoping this will look nice with the Hengstler counter and the grip I've published earlier. T-tracks, magazine, magazine holder and scope are in the making, but I'm not entirely happy with them yet.