Made of high-tech proprietary glass filled nylon RX. Provides better impact resistance than standard glass filled nylon. Does not absorb moisture like phenolic, and offers better floor preservation than ductile steel or cast iron. Resists most chemicals, solvents, gases, acids and steam cleaning. Top plate measures 4 x 4½". Black tread color. 85 (+/-5) Shore D. Wheel core material is glass filled nylon<br>RX. Made in Canada. 3 year warranty.<br>Features:<br>* Order by 6 pm for same day shipping.<br>* Made of high-tech proprietary glass filled nylon RX.<br>* Provides better impact resistance than standard glass filled nylon.<br>* Quantity quotes available.<br>Order online from Box Partners today.