This hose from Kokido belongs to the ordinary upkeep of a pool. It is the link between the vacuum head or brush on the floor and the skimmer or suction fitting of the pool: the water, with the dirt in it, runs through the hose to the filter pump.
The wall of the hose is ribbed and spiral-wound. That keeps it supple enough to steer across the floor and along the walls, and stops it from kinking shut the moment you take a corner. At regular intervals along its length there is a smooth, reinforced section.
The hose arrives as a single coiled roll, strapped up, in blue. Measure the fitting on your own suction inlet and vacuum head before ordering, because that size decides whether the hose will fit them.
Meant for anyone who looks after their own pool: to replace a worn hose, or to keep a spare in the house before the season starts.