These replacement blocks are made out of staple set horse hair.

While requiring more maintenance than a synthetic pad, a hog or horse hair brush, will cut through frost, better than a synthetic pad.

Note: 

The Horsehair Head only fits on Reactor 2, Vector, and Olson's 8" brooms. If the pad on your existing Olson's 8" Broom is square; you have the older style broom, and the horse hair block is incompatible with this style of broom.