SLR Dimpling Jig Gas Block .625. These AR Gas Blocks made by SLR are constructed from durable 7075 billet T6 aluminum. To assist with the dimpling process the SLR AR-15 Gas Block Dimpling Jig features 5 position flats for vise-mounted drilling that will help you clamp the device for optimal stability. Instead of sending your rifle to a gunsmith pick up an SLR Gas Block Barrel Dimpling Jig to drill the dimples yourself. Please note that a 5/32in drill bit is required to successfully use this tool and is not included with purchase. The color of your jig is selected at random from the following options: Blue Black Orange or Green. Unfortunately we cannot guarantee your preferred choice of color at this time. We apologize for the inconvenience. Specifications for SLR Dimpling Jig Gas Block: Manufacturer: SLR Color: Black/Orange/Blue/Green Fabric/Material: 7075 Billet T6 Aluminum Condition: New Features of SLR Gas Block Dimpling Jig: 5 spacing for blocks with .400in / .425in / .450in / .470in and .500in center to center 5/32in drill bit required 7075 Billet T6 Aluminum 5 position flats for Vise mounted drilling to keep barrel stable Color of jig selected at random from the following options: Blue Black Orange or Green Numbers on Jig face the front (towards muzzle) Spacing to be used goes on DIMPLE side with drill bushing (opposite gas port) If using one dimple only always dimple under gas port Package Contents: SLR Gas Block Dimpling Jig Hardened centering screw Custom hardened drill bushing SLR DJ6: Dimpling Jig Gas Block .625