Atlas Custom Works Tokyo Marui Hi-Capa GBB 3.9" Type 4 No Marking CNC Aluminum Frame, Gold

The Atlas Custom Works 3.9 Type 4 frame is for building a compact Tokyo Marui Hi-Capa GBB from the ground up. At 160mm, it's shorter than the standard 5-inch Hi-Capa, which means better concealment and a different balance for competition stages where you're drawing and engaging multiple targets. This is the skeleton of your build—the rest of the pistol comes from you.

What you get. The frame ships with a stainless steel sear, valve knocker, and pin set. That's the core fire-control group you need to mate with a compatible slide and barrel assembly. It's designed specifically for Tokyo Marui Hi-Capa GBB platforms, so don't try to force it onto a different pistol.

No Marking compliance. The "No Marking" designation means the frame has no serial numbers or permanent markings. In some regions this matters for legal compliance when building a custom GBB. Check your local laws before you buy.

Gold finish. This is the gold-anodized variant. The finish is cosmetic—it doesn't affect function. If you're building a match pistol where you need to identify your gun quickly on the range, consider whether a bright finish helps or if you prefer something more subdued.

What you still need. This is a frame only. You'll need a compatible slide, barrel, hop-up unit, outer barrel, and gas system to complete the pistol. You'll also need a magazine that fits the Hi-Capa platform. If you're new to Hi-Capa building, talk to a technician about parts compatibility before you start sourcing components.

Installation. Frame swaps on GBB pistols involve disassembling the entire gun and can affect reliability if not done correctly. If you're not experienced with Hi-Capa internals, have a certified technician handle the build. Performance depends on proper installation and the quality of the other components you choose.