AS Designs Super Safety MP5 Lower (Full Kit)

The AS Designs Super Safety MP5 Lower is a complete, machined AR-FCG MP5 lower built to run a Super Safety selector, sold as a full kit so you are not chasing parts. The receiver is CNC billet 7075-T6 aluminum with a Type III hardcoat anodized finish, machined specifically for super safe or Arc-Fire action. Because it uses an AR fire control group rather than the factory MP5 housing, it is the host that products like the Trinity trip kit and the AS Designs Slip Trip are designed to feed.

The full kit is the value here. It includes the AS Designs Super Safety M2 Tool Steel Kit (curved trigger) or the Arc-Fire V2 Kit, a mil-spec fire control group, anti-walk pins, an AR grip, a Slip Trip V5, and a custom ejector lever. The Super Safety is a selector, not a trigger; its added position is what enables forced reset behavior, with the Slip Trip on the bolt carrier doing the mechanical reset. A stripped-lower option exists at the same $399.99 for builders who already own the internals.

Fitment is model-specific. This SKU is the H&K SP5 and SP5-L lower, and AS Designs states plainly that it does not fit HK94 shelf guns, Century, PTR, MAC, or Zenith. Those platforms have their own AS Designs lowers. At $399.99 the full kit undercuts the complete Mars and Rare Breed units while still arriving as a buildable, mostly-finished system. It is direct from AS Designs. Verify current federal, state, and local law before purchase.