ShaloTek FLEX Lock Block Black. This component sits in the FCU housing to lock in your FCU. Specifications for ShaloTek FLEX Lock Block: Manufacturer: ShaloTek Color: Black Fabric/Material: 416 Stainless Steel Gun Make: SIG Sauer Gun Model: SIG Sauer P365 Features of ShaloTek FLEX Lock Block This part is made for the ShaloTek FLEX 365 Package Contents: ShaloTek FLEX Lock Block What firearm models does the manufacturer say ShaloTek FLEX Lock Block is compatible with? The manufacturer suggests that ShaloTek FLEX Lock Block is compatible with SIG Sauer P365ShaloTek F-LOKBLK365: FLEX Lock Block Black