Whether belaying is your favorite or unpopular actions, selecting the correct belay and rappel devices should definitely not be underestimated. Belay device with assisted braking as Petzl Grigri, are especially very pleasant for protection. They do not limit you as belay device without assisted braking function, so they are particularly suitable for sports and climbing on indoor walls. Belay devices without assisted braking functions such as eight or ATC will help especially in the mountains or in the traditionals ascents, where are greater demands for protection (especially larger rope slippage). Also ATC are suitable  half and double ropes. Increase your safety and confort  - the right belay devices will give you confidence and thus higher sports performance.