I used to make my own Thumb Rests from exotic wood 'pen blanks' for basses where it's tricky to find a place where to anchor your thumb, like Ibanez EHB's. The Thumb Fin is a fantastic solution. I actually removed the suction cups and used 3M double sided tape pads to attach the Thumb Fin to the top of the EMG pickup on my Steinberger (like) bass. This makes it 100% more comfortable to play.
I play an Acinonyx bass, so you can't drill into it to place a 'normal' thumb rest because of wiring, this works perfectly! Highly recommend.
You can find exactly the spot you want WITHOUT drilling holes. Worth every penny...
I bought one for my Sting Ray, one for my Epiphone Jack Cassidy, and one for the Fender Jaguar bass. Very versatile, don’t drill into that bass!!!!
Product is exactly as described and arrived with days of order. Very satisfied and would recommend to anyone.