Mer = everyday carrier that can go in water! Soft swim nylon and soft board short material plus some special foam, allow these carriers to be worn wet or dry. Swim material is light and breathable just like your swimsuits!
Duo means tandem compatible. Buy any Duo Onbuhimo and any Duo Full Buckle to tandem carry. Pair the same fabric/print to match or mix it up and get the best of both worlds!