Listing is for four (4) 3" diameter thermoplastic rubber wheels and a 3/8? diameter ? 16 TPI x 1.5? threaded stem with a side lock brake. Supports up to 110lbs per caster. When searching for a reliable and durable solution to your furniture needs, consider Service Caster?s Series 05 polyurethane, thermoplastic & soft rubber casters. The Service Caster 05 series is ideal for light duty applications, and is the perfect solution as new or replacement parts for chairs, tables, medical carts and other home and office furniture. This durable caster provides easy maneuverability for a smooth and quiet ride, and features dual ball bearing heat treated raceway construction, with a zinc plated finish that provides durability under any condition. Wheels are available in non-marking polyurethane, thermoplastic rubber and soft rubber, excellent for carpet, concrete and tile floor surfaces. Mounting options include top plate, grip neck, grip ring and standard and metric threaded stem sizes. Also, the innovative expanding stem, that can easily adapt to the inside diameter of an opening, allowing for a secure fit in round or square tubes.