Motorcycle batteries

In technical climbing, a skyhook is a very small hook which gives hold on smallest protrusions, or watery and slippery grips.
They are most often used for placements, often extremely marginal, in aid climbing, although they also feature in some extreme free routes. Additionally, the skyhook can be attached to the harness, thus allowing the climber to rest, or held in one or both hands to hold a grip.

In the industry, a skyhook can be used to haul someone or something up to a ceiling for repair or maintenance purpose.