There are three main types of devices:
- Tube Style (also called manual or standard belay devices)
- Auto-locking (also called auto-assist or self-locking)
- Auto-blocking (also called guide's style)
Which style you use depends on which application you are using it for.
Tube Style belay devices are handy and well priced for traditional belaying and rappelling methods. This is the type of device you get when you first start climbing and will probably hold onto forever. There are many choices on the market that work generally the same way. Cost depends on size, weight and additional features.
If you're planning to get off the deck for more than one pitch, many climbers bring an auto–blocking device. This way they can belay directly off the anchor, thus saving energy. You can tell a guide’s device by its additional, full–strength, clip-in point.
These devices are great because
1. Belaying off the anchor is less effort than off your waist.
2. You can escape the belay (you've already escaped when setting it up).
3. Works great for lead, following or rappelling; they are very versatile.
These devices only work with a single rope of a specified diameter. They are ideal for situations where you are either belaying for a long time (big walls) or are going to have a climber who is hanging a lot on the rope (gym, sports climbs, cragging). These devices are generally heavy and expensive (except for the Mammut Smart, which is light and cheap). Because they only work with a single rope, you need to also bring a tube style or auto-blocking device if you want to rappel two ropes.
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What diameter ropes you intend to use is very important. Some devices won't work for small ropes while other devices won't perform well with thick ropes. Make sure to check out our Ratings Overview tab above so that you can see which device will work with which diameter rope and which device will work with two ropes. For example, our top rated auto-blocking device did not do very well with thick ropes. Almost all tube style devices work fine in the gym on 10.5mm ropes but have much different handling characteristics if belaying on a 9.2mm rope.
Durability is something to consider when purchasing a belay device. But honestly, it's the least important point. How the device handles is definitely most important. Most climbers, with moderate use, can go many years before they wear out their device