There are several classes of descent devices. One way of classifying these systems is by how much the person descending must use his or her hands to operate the system, either to stop, to go, or both.
Each has advantages and disadvantages in rescue applications. Let’s look at each…
1. HANDS-ON ALL THE TIME
This includes the figure-8 and ATC. The primary advantages of these types of descent devices are that they are extremely inexpensive (typically less than $50) and very light weight. In trained hands, they are very versatile and can be used with a range of rope types and sizes. The light weight and low cost make them the choice of rock climbers. They are also used by professional rescue teams because the people on those teams often have a rock climbing background.

A figure-8 descent device.
The disadvantages of these devices are that they require significant training, the consequence of misuse is disastrous, they cannot be used if your hands are injured, and they are not generally suitable for work positioning because there is no “stop” function.
2. HANDS-ON TO “GO” AND HANDS-OFF TO “STOP”
These systems, which include the Grigri, EXO, ID, Escape Artist and F4, all require the use of your hands to initiate and control descent. One hand is needed to release the brake and the other hand must be on the rope to control descent speed. They also have an auto-stop function that allows you to stop and hold position by removing your hand from the brake to release it.

The Grigi is one example of a descent device with an auto-stop function.
The common mistake people make with these devices is thinking that descent can be controlled with one hand -- just the hand that releases the brake. Descending with only one hand is how people get hurt because descent speed cannot be controlled with the brake release.
3. HANDS-ON TO “STOP” AND HANDS-FREE TO “GO”
A number of companies make gear-driven centrifugal-brake devices that fall into this category. Centrifugal brakes control and limit descent speed, so they are called “controlled descent devices” rather than just “descent devices.”
The advantage of controlled descent systems is that the “go” function is hands-free, which also means that free-fall is avoided (barring system failure). These devices provide a level of safety unmatched by the previous two types of devices. However, these devices do not have a fail-safe hands-free “stop” function. Rather, these devices typically require the user to hold the unloaded side of the rope and pull on it to stop or slow descent.
Other devices in this class have one or two stopping mechanisms.
- Some provide a “pigtail” around which rope can be wrapped in order to increase friction. Stopping or slowing descent with a pigtail still requires holding the unloaded end of the rope with your hands.
- Other systems provide a cam cleat as a stopping mechanism, like that used on sailboats. The cam cleat is not used to slow descent. Rather, it is used to secure the unloaded end of the rope once descent is stopped so that position is maintained without slipping. The problem with cam cleats is that they are not designed for life-safety applications. It is an unsafe practice to put a rope in a cam cleat and then take your hand off the rope.
4. HANDS-FREE TO “STOP” AND HANDS-FREE TO “GO”
The models in the DEUS 3000 Series are the only controlled descent devices in this category. These devices use a direct-drive centrifugal brake to control and limit descent speed, allowing for fully hands-free operation. Like the devices in the previous category, DEUS 3000 Series devices protect from free fall. However, that is where similarities with devices in the previous category end.
DEUS 3000 Series devices have a control knob and an additional internal drum brake that can be used as a throttle to slow or stop descent. Once the control knob is turned to slow or stop descent, it holds that position, or holds that speed, hands-free. Pigtails and cam cleats used in the previous category are brakes that should not be used hands-free. By contrast, the control knob that sets the drum brake on DEUS 3000 Series devices is designed to be used hands-free.
The advantages of controlled descent devices that are hands-free both “stop” and “go” include:
- Significantly increased safety at any speed
- Less training required for safe operation
- Improved versatility because one device can be used for any situation'
- These devices can even be used by people with badly injured hands
The controlled descent devices in the DEUS 3000 Series are designed to be used hands-free at any speed: stop, slow or go. This makes the DEUS 3000 Series the ultimate solution for safe, reliable and versatile evacuation, rescue and work.