NOT FOR USE ON A LAWN MOWER - THESE ADAPTERS ARE ONLY FOR USE WITH A BLADE BALANCER.

Hole Adapter bushing - Jacobson - Double "D" style (9/16" wide x 7/8" diameter).

Blade hole adapters are for lawn mower blades that do not have a circular hole, these adapters allow you to mount these blades to a MAG-1000 Series Blade Balancer.