Simple, easy and safe to install (no need to use the palm of your hand). Each spinner comes complete with 5 shaft adapters (5mm, 6mm, 1/4", 7mm, 5/16" shafts). Features a unique nylon insert lock design for attaching the back plate and spinner - giving a solid and secure hold. Designed with safety in mind.
Use Allen Wrench size 5/64" (not included).
Diameter: 1.75 inches (44.45 mm) at base.
Length: 1.75 inches (44.45 mm) from baseplate to tip.