Given that safety is always paramount while climbing, the Petzl Shunt adds security as a back-up device. Offering a mechanical replacement for self-jamming knots (mechanical prusik), this tool is designed to lock onto either single or identical double ropes in the event of a technical error or slip. Providing versatility, the Shunt adds braking security on double rope descents, belaying a second, or can function as an occasional ascender.