Volquartsen Firearms Posi-Lock Bolt Latch for MKII and MKIII Silver. Our new Posi-Lock Bolt Hold Open Latch has been engineered to withstand years of use for even the most demanding shooter. Manufactured from hardened A2 tool steel this latch contacts the bolt in a more effective way in order to ensure the bolt locks open on each and every empty magazine. Included Accessories: - Fits both the Ruger MKII and MKIII pistols (does not fit the 22/45 model) Specifications for Volquartsen Firearms Posi-Lock Bolt Latch for MKII and MKIII: Manufacturer: Volquartsen Firearms Color: Silver Gun Model: Ruger Mark III Ruger Mark II Country of Origin: USA Package Contents: Volquartsen Firearms Posi-Lock Bolt Latch for MKII and MKIII What firearm models does the manufacturer say Volquartsen Firearms Posi-Lock Bolt Latch for MKII and MKIII is compatible with? The manufacturer says that Volquartsen Firearms Posi-Lock Bolt Latch for MKII and MKIII is compatible with Ruger Mark II Ruger Mark IIIVolquartsen Firearms VC3BHL: Posi-Lock Bolt Latch for MKII and MKIII Silver