Rings are very strong yet comfortable, and the bands can easily withstand more than 400 kg (tested). It took me a while to find a way to tie them so that they are both stable and easily attachable, modifiable in length. Once tied however they provide an entire range of body-weight exercises either as a warm-up or finishing your training. Most useful for stretching and resistance, complex exercises: hanging planks, shoulder & biceps tension training. Can also be used with weights or just securing the bar to the rig in order to prevent injuries.