The Powerline Leg Extension and Curl Machine is designed to develop your quads and hamstrings while protecting you joints from stress. This machine allows the user to perform both in traditional upright and prone positions. It features side stability handles and foam rollers when being upright and prone, The weight post is 1" in diameter, and is used with standard plates. You can purchase an Olympic Adapter Sleeve if you want to use Olympic weight plates. Weight plates and collar sold separately.