Sloting Plus Monaco pattern wheels for 3/32" (2.37mm) axles - 16.5mm diameter x 9mm rim width - aluminum  / magnesium alloy - light weight 1.1g with setscrew - M2.5 setscrews for larger hex size to prevent stripping of hex wrench sometimes an issue with M2 size setscrews - 2 wheels / package with setscrews