The monofin of Suntail are patented world-wide and are expelled by the mermaids swimming school® in Switzerland. With the KEIKI and the NUNUI two different models are offered. The KEIKI is suitable more smally and more lightly cut and therefore for children very well. The NUNUI is little bit bigger and more difficult and is suitable is suitable for young persons and adults. The products exist of a synthetic material fin and in each case to a neoprene foot part. The foot part can be exchanged simply and comfortably, this should be faulty. The best takes part that the use of the Monoflosse is also possible without suit.