This type is inserted into the gap next to the bridge, in the wing section. It's about 6mm thick. It picks up sound just by touching it, so it seems better not to push it too hard into the gap. The output jack part will be fixed to the tailpiece, etc., with an arc-shaped clip or a cable tie. It's new, only tested for operation, and has a handmade feel. I've been trying various things, but the female phone jacks all have their pros and cons. This one is a copy of a Switchcraft type, but unlike the ones sold at Soundhouse, I've made it the type that clicks when you insert it. Please let me know if you experience any issues, such as poor compatibility with L-shaped plugs, etc., when using it.