Not only does the Petzl Reverso Belay Device give you serious stopping power when you're holding massive whippers, but it also functions as an auto-locking device when you're belaying the following climber directly off the anchor. This allows you to re-rack, tie your shoes, sip some water, and take a few photos without risking your climbing partner's life. Belaying two followers at once? No problem. Rappelling 15 pitches? The deep grooves give you plenty of control.