Item fits flush and install is easy once you figure out how to do it - Tactical Precision Manufacturing TPM Sig P365 XMacro 3 Round Extension

This extender fits flush to the Maxwell unlike my other 3 round extender, but it is exceptionally larger for the additional 3 round capacity and does print more than the other I purchased. I don't think I would run this in my EDC due to that but the weight and overall aesthetics are clean. When you get the part there won't be any install instructions and it comes wit ha tiny Allen key. You will need to pop off your existing base plate and after sliding this one on, you would use that tiny Allen Key and insert it in both the bottom holes of the Extender and then tighten the screws to then push them up against the magazine. The Allen Key goes in at a steep angle to get to the screws and you might think that it is not placed in correctly or will not work but trust me it does.