Keiki monofin is considered a starter monofin. The feet are secured by putting the feet into 2 big footpockets. The ‘socks’ fits around the ankle to secure the fin. Narrow ankles or feet will loose this monofin easily. It is better to choose the Linden or Mahina monofin in that case.
Want to upgrade? Tails made for the Nunui monofin will also fit the Linden Monofin