8"" PNEUMATIC CASTER KIT FOR RUBBERMAID TRADEMASTER MOBILE WORKCENTERS PNEUMATIC CASTER KIT PROVIDES SMOOTHER OPERATION ON ROUGH SURFACES. SET OF FOUR 8"" DIAMETER X 4""W CASTERS. FITS 4520-10 & 88 4525 4530 4531 4532-88 4533-88 4546-00 & -10 4547 & 4548-88 CARTS. KIT CONTAINS 2 SWIVEL 2 RIGID AND HARDWARE WARNING: This product can expose you to chemicals including lead which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65warnings.ca.gov - 1,3-Butadiene