Johnson' Handy Lock 02 Series stainless steel turnbuckle for shrouds, stays and tie downs has two flip handles for too free adjustment. It positively locks the turnbuckle without cotter pins or check nuts. There are no sharp points to catch lines or tear sails, just flip the levers to adjust and down to lock. The 108 is the Jaw & Swage model and is not calibrated. It is designed for 1/4 in. (6mm) wire and 3/8 in. (9mm) thread size.
Johnson recommends that working loads not exceed 40% of the approximated breaking strength.