Abstract: A device is formed with two hinged half-collars for opening and closing around the breast, which half-collars have specifically contoured inside surfaces which surfaces correlate to orthogonally projected curves which intersect at an angle slightly less than 180.degree. but not less than about 160.degree. over the useful clamping of the half-collars, to effectively clamp the breast while avoiding pinching during clamping of the half-collars on the breast.