Quality construction and fully tested. Extremely versatile and fast. This size fits 12 gauge Standard Invector. This is perhaps the best, most versatile choke tube design ever. The T-Wrench allows more torque to be applied with greater leverage. Ideal for chokes that have experienced heavy shooting and that might be a little sticky. Fits Standard Invector. This is perhaps the most proven and effective choke tube wrench design ever. And the design is proven with every gauge over the years -- but it all started with this design in 12 gauge.