The XMark Two Black Zinc Olympic Spring Collars with Plastic Grips XM-3606 ensures that your plate weights are held firmly in place during lifts. This will allow you to maximize workout potential by preventing weights from sliding or falling off the bar. A black zinc finish on these well-crafted spring collars provides a rugged appearance and plastic grips enable their easy addition to and removal from the bar. The XMark Two Black Zinc Olympic Spring Collars with Plastic Grips XM-3606 gets the job done, keeping plates attached snugly to your bar.