These 4 inch diameter Wheels fit the Chesnik Scopes and are designed to be interchangeable with their kaleidoscopes. We have 6 different 4 inch diameter wheels available. They are available in Brass or Chrome Finish. There is a 4 inch Chrome primary dichroic glass Wheel $66.00
a secondary 4 inch Chrome Dichroic Glass Wheel $66.00
there also is a 4 inch fiesta Wheel $94.00
4 inch Chrome agate Wheel $66.00
4 inch Chrome stained glass Pie Shaped wheel $60.00
4 inch Chrome seashell Wheel $66.00
I measured the hole and it is just under 1/8 of and inch diameter hols in wheel i would say between 3/16 and 1/8 of an inch hole.