Smart Pins replace push pins in shroud turnbuckles. Now you don't have to tape shroud turnbuckles to protect sails from cracks caused by sharp cotter pins. Smart Pins are stainless cotter pins that are integrated into a UV and saltwater resistant Velcro strap. The cotter pin is inserted into the shroud tensioner and the Velcro is wrapped around the tensioner a few times. You can remove Smart Pins just as quickly and easily when the rig needs to be trimmed. Price per piece. Fits W mm H mm L mm Pin mm 1/4" Tensioner 16 8 150 2.0 5/16" to 3/8" Tensioner 16 10 190 2.5 7/16" to 1/2" Tensioner 20 13 260 3.2 5/8" to 3/4" Tensioner 25 20 370 4.0