Aero Precision SOLUS Action Wrench, Specifically Designed to Torque the Aero SOLUS Action, Matte Finish Black APBG300027C The SOLUS Action Wrench is specifically designed to torque the SOLUS Action to a shouldered barrel. It utilizes a three-lug wrench tip" like the bolt that is replaceable. This is a must have tool if you are using a shouldered barrel.