These ascenders lock in one direction and can be pushed, nearly friction free, in the other. They attach midline on ropes measuring 8 to 13 mm (5/16 to 1/2 in. dia.) and have a spring-loaded safety latch that must be manually tripped to insert or remove rope. Left hand oriented with the latch located thumbside for convenience and safety. Holes provide clip-in positions, depending on the application. Made of lightweight aluminum, with formed handholds for comfort. Ascender Right HandGold Petzl.