The Petzl Catch is a spring-loaded lock which helps keep the climbing line in the Petzl Pantin during rope ascents - the Petzl Pantin needs to be purchased separately. Or… easily retro-fitted to your existing Petzl Pantin using the pre-drilled hole on the cam. The Petzl Catch can be locked open not unlike the mechanism on a hand ascender. The 'clip-in' and the 'clip-out' feature of the Petzl Pantin are lost when you add the Catch. The device is available for PANTIN in right- and left-foot versions.