Works great but you need the sig lower - SB Tactical MPX Pistol Stabilizing Brace for SIG SAUER SIG MPX and SIG MCX

I purchased the PDW-style brace for my Rattler build but I was not originally using the MCX lower for the build, I purchsed the MCX conversion kit from Sig. Because of the width of the gas tube on a standard AR lower receiver, the rails of the brace are not able to be collapsed. In the meantime i used a spare folding brace for the build. I have since purchased an MCX lower and the PDW brace fits perfectly. No issues with the part itself, but just know that you NEED the MCX lower for this product to work