The 6" x 1-1/4" (150x30) pneumatic mobility tire with K671 Slick tread may be used on some scooters, power chairs, and a few wheelchair casters. The K671 Slick tread is lightly siped (grooved) to disperse water but not cut deep enough to pick up small pebbles. Made of non-marking gray rubber, this pneumatic mobility tire requires an inner tube (sold separately).