My dear man! Got a bit too excited, I have measured the grommet and 30mm is significantly smaller!! My bass is donkeys years old and it has its own grommet that is a big clunker!! In order to replace it and get one of these fancy lovely carbon pin my luthier will have to do more work than I wanna fork out for, so as tempting as it may be the old wooden grommet and leg might have to stay!!! I had my hopes up without making any measurements. Sorry dude, keep well and hope you sell it fast! Timo