The problem with sexual performance is that there's never been an effective way to train... until now. The Endurance Jack comes with a specialized masturbation sleeve designed to challenge your longevity. You won’t be able to resist shooting your load, but the longer you can train yourself to endure, the longer you’ll be able to maintain with the real thing. Endure with this jack and you’ll be a legend in the sack! The Endurance Jack comes with the signature silver case.