A releasable band-clamp coupling for mechanical and hydraulic interconnection of the end of at least one first cylinder and a second cylinder or connecting means, said coupling comprising: a) a central housing of cross-section resembling a wide, low-wall channel having walls (18, 20) facing away from the center of said cylinders (12, 14), said housing curved to be larger than the outer diameters of said cylinders (12, 14); b) two curved outer clamp members (24, 26) configured to contact a wall of said central housing, and which support at least one circumferential elastomeric seal member and a sloped internally-toothed grip ring, clamping extensions (44, 46) being proximate to the ends of said curved outer clamp members (24, 26); and c) a screw clamping element in contact with said clamping extensions (44, 46) to reduce the distance between said clamping extensions (44, 46), forcing both said sloped internally-toothed grip ring and said at least one circumferential elastomeric seal member into circumferential contact with said cylinders (12, 14); wherein said sloped internally-toothed grip ring comprises a plurality of spaced-apart wedge-shaped gripper units (50, 64), adjacent gripper units (50, 50a, 50b) being connected by a wave-form flexible element to complete said grip ring, and wherein said outer clamp members (24, 26) are each configured to make side contact with an inner face of the central housing wall, and a central portion of the outer clamp members (24, 26) houses said elastomeric seal member, and an outer portion of the outer clamp members (24, 26) is sloped inwards about 25-45 degrees and houses said sloped internally-toothed grip ring; characterized in that each of said gripper units comprises two separate parts, an inner face arranged to contact the cylinder being gripped, and an outer wedge-like portion configured to support, retain and apply pressure to the inner face, said inner face being configured to retain said flexible element, said flexible element being released when each of said gripper units is separated from the inner face; a multitude of elements projecting from said inner face in a manner that in operation said elements are forced into contact with the cylinders (12, 14) being coupled; and wherein the multitude of elements are either supported directly by said inner face or the multitude of elements are supported by an inner cone projecting from said inner face. a) a central housing of cross-section resembling a wide, low-wall channel having walls (18, 20) facing away from the center of said cylinders (12, 14), said housing curved to be larger than the outer diameters of said cylinders (12, 14); b) two curved outer clamp members (24, 26) configured to contact a wall of said central housing, and which support at least one circumferential elastomeric seal member and a sloped internally-toothed grip ring, clamping extensions (44, 46) being proximate to the ends of said curved outer clamp members (24, 26); and c) a screw clamping element in contact with said clamping extensions (44, 46) to reduce the distance between said clamping extensions (44, 46), forcing both said sloped internally-toothed grip ring and said at least one circumferential elastomeric seal member into circumferential contact with said cylinders (12, 14);