Lightweight sprung type chain tensioner replaces derailleur for running a 1-speed drivetrain on a vertical dropout frame. Variable tension and position (can be used on rigid frames or suspension frames with varying chain length). Supplied with 2 springs to provide pull-up or push-down function. Superlight CNC machined alloy body, pivot bolt and sealed bearing pulley. Steel no-jump guide cageItem Specifications: Color: Black, Model Name: Squire Chain Tensioner, Mount: Derailleur Hanger, Weight: 96g,