The build quality of the Rings is good and also the size and visibility is sufficient. We use them as part of the DLRG education as diving rings for children and young people swimming lessons at the indoor pool at a depth of approximately 1.80 m. They should be used there either as orientation or turning point or for recording by the dynamic apnea.
The sinking speed is ok, unfortunately the rings are much too easily and are driven off after a short time - even if they already are at the bottom of the basin. For this purpose it takes is a very slight flow past a floating person (there are no underwater jets or the like exists!).
