These are 1/4″ shank (the threaded part length). These use 5/64″ Allen Driver.

These are long enough to accommodate most aftermarket
grips yet short enough to still work with some factory grips. The LARGER HEAD may not work with some grips, but it does add more tightening surface, like a washer.

These screws also have a lower profile than factory, so won’t protrude past the grip surface where other screws might.