The Lock-Jaw Standard barbell collar features a solid nylon resin frame and injection molded pressure pads, making it nearly unbreakable. The single-action cam lock securely clamps the collar once positioned on the bar. Lock-Jaw collars will withstand the toughest workout environments. Same design as the Olympic version, but this model fits the standard (1-inch) bars and NOT the 2 inch Olympic bars. 4 ounces per set. 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.