There's no doubt the classic 8 descender from Kong, ISC and other hardware manufacturers is one of the most popular descending devices on the market. It's simple, versatile and economically priced. But most classic and rescue 8's have one major failing - you have to take them off your harness in order to install the rope and in the process you increase the risk of dropping equipment.
The Petzl Pirana offers an excellent solution to this problem.Originally designed for the demands of canyoning (where dropping of equipment is not an option) the Pirana is permanently attached to a carabiner. It'sdesigned to pair with the Petzl William but any carabiner with a 12mm circular bar would suffice. The black 'hard-rubber' stopper keeps the Pirana in placeby providing a tight fit to the bar thereby combining the two individual items into one fantastic descending unit. When used with the William the Piranafolds into the basket of the carabiner making it a very tidy unit on your harness.The Pirana can be used right or left handed and offers three descent positions and two additional braking options making this one of the most versatiledescenders on the market. It's primarily designed for single ropes but it can be used on double ropes up to 13 mm in diameter.