yet ensures they'll stay firmly in place. Solid frame construction for superior durability. Fits any 2 inch Olympic-style bar. 2 inch diameter nylon resin collars.  Sold in pairs Since 1986, Power Systems' passion for fitness has been fueled by our customers. Power Systems is committed to ensuring people have the tools to lead active lives with professional-grade products, cutting-edge educational materials, and elite customer service. “Power Your Potential” is the philosophy that guides everything Power Systems stands for.