This is a very well-made tool at a fair price, hence the 5 stars. I play the gamba and it was a little on the wide side for my purposes, although eventually I got it through a 12 mm f-hole. Maybe we need a specialist gamba setter rather than having to rely on cello and double-bass ones? It's also a good idea to state the size of your f-holes when ordering. Maybe this question should be on the order-form?