There are two main types: (1) Sit-harness (2) Full-body type.
The first type is the most common and can be used in most situations. The Full-body type is more useful and comfortable when having to sit for long periods at a time, hanging on the rope. They also eliminate any danger of the wearer slipping out, if they turn head down while descending.
When putting a harness on, all the buckles must be double backed straight away unless they are of the auto-buckle variety. It must be fitted so that it is firm all around the body. A Sit-harness must be adjusted so that the waistband is well above the hips.
Harnesses have “gear loops” around the waist belt. Never use these loops for any other use other than carrying equipment. They have a breaking strength of only about 15 kgs. An extra safety tip to remember is that when you are clipping to the rope, make sure that loose fitting clothing does not obscure your vision of what part of the harness you are clipping to.
When connecting a belay rope to an abseiler, it is best to always tie the rope directly into the harness, using a re-threaded Figure 8 knot. Using a karabiner is quicker but this has two dangerous aspects; firstly, in the event of a fall, the karabiner maybe in a cross-load situation at the moment of impact. Secondly, there is simply another link in the system, which may not be properly connected.
The abseil devices such as a Figure “8”, is always clipped on with a Screw-gate karabiner into the belay loop provided on the harness. It is also very important to follow the manufacturer’s advice about where and how to use the harness. These instructions are always provided when buying a harness.