Single Lok-Up Halyard Line Lock w/Bungee Rupp Lok-Ups are an innovative locking pulley system that locks your halyard lines, keeping your outrigger release clips right where you want them. Single Pulley with 12″ for Single Rigging. Robust design that includes the following: Spring loaded trigger for positive locking and unlocking. Modular design that is adaptable to various rigging setups. Accepts a wide array of halyard line material and thicknesses.