The 1M version of the SG 543 is a modernization to the 543 platform, currently in use with Chilean military. The modernization includes flat-top picatinny rail, folding telescoping polymer stock and picatinny quadrail in order to enhance the rifle’s capabilities and provide ability to tailor the rifle towards various mission requirements. The long barrel SG 543 was specifically developed in order to provide a lighter front-end in contrast to the SG 540-1M with full-length gas system and quadrail. This shipment was 3.5 years in the making, stock is limited.