Each CLAM provides 1 cm of inboard and is a convenient alternative to moving buttons if your crews are sharing oars between an eight and a four, you'd like to quickly test different loadings with your crews, or you find yourself in a headwind after a long row. They also provide a great wear surface between the collar and the oarlock.
Important: CLAMs are designed for use with current production Concept2 sleeves only and may not fit properly on other sleeves.