I needed 1/4-20 thread 3/4" length for my pre 2011 wake boards I own. For the 2012 and up you'll need the M6 thread 3/4 length. Anything longer and you'll need a plastic washer to take up the space. The white washer allowed me to use a 7/8" length 1/4-20 but not the 1" length. Hope this helps. I also discovered with my Connelly Reverb new board 2022 model, when I installed my Liquid Force Index bindings with my stock M6 screws 3/4" length they needed a 1.5mm thick washer.