Great for tightening the inputs on my guitars (Fender AVRI strat, Fender Mex jazz bass, and more). Just remember to always unscrew the input-plate first, so you can hold it in place while tightening it, otherwise it'll turn counter to your tightening inside the guitar, and eventually tear loose the attached wires. This tool is very slim, which is nice, so it is possible to get at all kinds of jacks without the tool getting in the way, unlike some of the bulkier ones. For example it works great for tightening the recessed jack in a stratocaster. Seems solid.