Abstract: A clamp comprising a band (10) having, at one end, a pair of axially spaced jaws (16, 18) comprising an upper jaw (16) and a lower jaw (18) and, at the other end, a tongue (28) that can be inserted between the jaws. The tongue has an upper surface and a lower surface and the top jaw (16) has a lower surface that includes a single engagement tooth (20). The upper surface of the tongue includes an engagement tooth (29) having a cavity (30) behind it that can accommodate the engagement tooth (20) of the upper jaw to hold the clamp in a closed position. The lower surface (48) of the tongue is provided with a recess (40) that accommodates the lower jaw (18) when the clamp is in the said closed position.