Extreme Engineering Ultra Low Mass Sear is manufactured from aerospace steel alloy and is extremely low mass due to innovative recontouring. Designed to be used for extremely light trigger pulls. Faster reset time due to low mass which reduces chances of following with very light trigger pulls. Sear bearing surface micro honed to produce that 2 lb. pull easily. Heat treated to 53-56 Rockwell C for extreme durability. Out lasts all other sears now on the market. Competition proven; Over 40,000 rounds fired on this sear mated to one hammer with no follows at a 2 lb. pull. Fits all 1911/2011 formats.