Electric Wheelchairs Pair of (2) Invacare Storm Series Wheelchair Caster Tires 8″ X 2″ (8″ X 1.75″) 200 X 50 Review Posted on July 24, 2018November 7, 2018Author Marauderby This listing is for a Pair of (2) Invacare Storm Series Wheelchair Caster Tires 8″ X 2″ (8″ X 1.75″). Light grey polyurethane tire with ribbed tread, precision bearing.