Musiclily 2R2L Sealed Bass Tuners Tuning Pegs Keys Machine Heads Set, Chrome

Something seems off with the listing specs of a 9/16" hole required . I doubt that would fit into any headstock I have ever seen. ??

will these fit an Ibanez acoustic bass?

My 2x2 chrome bass tuners came without the washers, so they are useless. Is there a way to get the washers?

How thick of a headstock will this fit on?