Davis Sailing Air-Flow TelsThese lightweight, ripstop nylon Air-Flow Tels attach to sails with waterproof adhesive locator disks-no holes required! Use Tels to see the air flow across the sails; this allows you to traim sails for maximum performance. The result is better boat speed, less pinching, and no guesswork about placing the jib sheet lead forward or aft.Features:Comes with 14 High Visibility Tels (in red and green)No hole requiredClick to Download Davis Air-Flow Tels Instructions