Spare o-rings for bandboards

Spare o-ring sets for Obstructures Bandboards include one replacement for each stiff A70 ring, and multiples of all other soft A50 rings. The set is a duplicate of the spares that ship with an original Bandboard. We have chosen these sizes for optimal performance. If you would like to order larger quantities or customize your Bandboard with more loose or tight rings, please pursue the selection at McMaster Carr