A modification the the #40 rear sight first fielded on the MK12 Mod 0 SPR. The #40 size worked well with the additional size of the Swan Sleeve rail. The request came in for a back-up rear sight as durable as the #40, but with a lower profile to be mounted on standard flattop rails on the M4A1 and the H&K 416 carbines.
The folding sight incorporates an innovative rear-leaning mechanism that ensures proper directional folding under impact, maintaining zero and extending operational lifespan. While compatible with MK12 platforms, this lower-profile design specifically addresses modern flattop mounting needs.
The A.R.M.S. #40L earned selection and contract approval from Naval Surface Warfare Center (NSWC) Crane for U.S. Special Forces deployment. The sight system demonstrates proven performance on M4 carbines and HK416 rifles, serving as a modern alternative to the A.R.M.S. #40 sight used on the MK12 Mod0 SPR platform.
A.R.M.S., Inc
A.R.M.S., Inc