Ritter & Stark continue their innovative thinking by offering conversion kits for their SX-1 MTR rifle series, enabling the user to perform a change of cartridge in a few minutes. Included in the kit is the threaded barrel (including brake), with attached rail (permitting a dedicated scope to remain affixed to the barrel at all times, thereby maintaining 'zero'), and the appropriate bolt face. In come cases, a magazine sleeve is included (depending upon the kit).