Tuber (Tubular belay device)
Tubular belay devices are the most commonly used belay devices during training of advanced climbing and rescue techniques, multipitching and management of twin/double ropes. In some countries/clubs, they have been replaced by assisted tubular belay devices for single-pitch training. They are prohibited in some gyms due to alleged security concerns (for details, see the security concerns section).
| Tuber | |
|---|---|
 | |
| Other names | Tubular belay device, ATC, Reverso, Guide |
| Use(s) | Belay, abseiling, rescue techniques, ascending (atypical) |
| Pros | Well-tested and optimized, super-easy to give slack, useful for belaying of the second climber (guide mode), lightweight, can be used with double/twin ropes, multi-purpose |
| Cons | Does not provide assisted braking function, it blocks only if dead rope is in the opposite direction to the live rope, can bite into skin of the brake hand index finger if used inappropriately, in majority of the devices the setup for lowering of a second climber is cumbersome |
Belaying risks
General risks
Always hold/control the break strand at least with one hand and keep the break strand downwards unless giving or taking the slack. Keep your hand at least a few centimeters from the belay device to avoid pinching of the skin. Do not lift your hand too high (above the device) while giving the slack. One of the commonly seen bad habit is keeping the hand raised for a prolonged time during belaying.
Always hold the break strand downwards unless feeding/taking the rope 
Feed or take the rope from the front of the device 
Not holding the break strand can result in fatal injuries 
Holding the break hand too close to the tuber leads to a risk of pinching the skin of the break hand index finger. 
Do not lift the break hand unnecessary high during the break strand manipulation. 
Do not leave the hand in the upper position if not taking or giving the slack.
Anchor-belay risks
Unlike during belay at a ground level, during anchor belay, climber can get below the tuber level in case of a fall, which leads to additional risks.
While belaying from the anchor, redirect the rope in a way that it points upwards even in a case of a fall. 
If the rope is not redirected properly, tuber rotates into a non-breaking position during a fall, which easily results into a ground fall.
Belaying from the harness
Slack taking
Start in the resting position 
Feed the slack through the device by simultaneously moving both hands 
Move the belay hand back into a fully blocking position 
Tunnel up the rope by the belay hand to the resting position 
Final resting state, repeat the steps if you need to take more slack
Slack feeding
Tunnel down 
Feed the slack through the device by simultaneously moving both hands 
Put the belay hand back into the safe resting position 
Final resting state, repeat the steps if you need to give more slack
Belaying from the anchor
Belaying second climber - tuber with guide mode
Setup for belaying second climber with a guide-mode tuber 
Taking slack is done by simultaneously moving both hands
Belaying lead climber - tuber with guide mode
While belaying from the anchor, redirect the rope in a way that it points upwards even in a case of a fall. Usually an unlocked D-shaped carabiner is used. 
This redirection can be also in some cases built by a quickdraw placed in the second bolt of the anchor if the carabiner is short and the bolt is placed high enough. 
Once the lead climber makes two secure running protections on the route, the redirection is removed.
Belaying second climber - tuber without guide mode
The same technique which is used for belaying the lead climber can be also used for belaying of a second climber with a tuber without a guide mode.
Belaying from harness at the anchor
During belay from harness at the anchor point redirects the rope through the anchor till the first two pieces of the running protection are placed. Otherwise if the climber would fall, belayer would be pushed downwards and at the same time the tuber would not block as both the break strand and the live strand would be pointed the same direction.
Abseiling
TODO (redirect to technique page)
Tuber as an ascender
TODO
Security concerns
TODO