Listing is for a set of four (4) Service Caster Series #30 casters, two (2) swivel casters with side lock brakes & bolt on swivel locks and two (2) rigid casters, with 3.25″ diameter by 2″ wide glass filled nylon wheel and maintenance free precision ball wheel bearings capable of supporting a total weight of 3,600 lbs. (900 lbs./caster). When searching for a reliable and durable heavy duty solution to your caster needs, consider Service Caster’s Series 30 glass filled nylon casters. The Service Caster Series #30 is ideal for medium and heavy duty material handling, carts, equipment, and shop projects. The zinc plated finish provides durability under any condition and the glass filled nylon wheels provide very low rolling resistance, show a high resistance to many aggressive substances, will not flat spot, and under normal operating conditions are maintenance free. Resistant to most chemical and oils, these glass filled nylon wheels will keep you safely moving forward. Service Caster is unsurpassed in quality, reliability, and excellent customer service. Count on us to move you forward.