Motion Pro - Slacksetter Pro Chain Slack Setting ToolSetting chain slack properly dramatically improves chain life. Accurately and quickly measure chain slack (not used to measure chain to swingarm clearance specification). Works on most street and dirt bike applications, up to 52mm (2") chain slack. Lightweight compact design fits easily in your tool box or road kit. Specifications Made from engineered nylon with aluminum measuring scale Anodized, laser etched, precision measuring scale Refer to your