Motion Pro Slack Setter Chain Tool Accurately and quickly measures chain slack (not used to measure chain to swingarm clearance specification) Setting chain slack properly dramatically improves chain life Light weight compact design fits easily in your tool box or road kit Works on most street and dirt bike applications up to 52mm (2 inches) chain slack Made from engineered nylon with aluminum measuring scale Anodized laser etched precision measuring scale Refer to your owner’s manual for proper chain slack and procedure