Also Known As:
It resembles a donut and slips over the handrail or ladder. The purpose is to cover the mounting point and the bolt that screws into the ladder wedge that holds the ladder and handrail into the mount.
This area of the ladder, if left uncovered, is a potential cut hazard for anyone entering or exiting the pool. This covering can be made from colored plastic or stainless steel. If made from plastic they will typically be white or chrome in color. Stainless steel is the most durable and will last the harsh elements.
The handrail portion that is located on the bottom entry step submerged under water in the pool would also need the same covering.