Abstract: An improved elastic band is disclosed having dimensions and design specifically adapted for tying off human fallopian tubes or similar internal, tubular members. The band of the present invention has an internal diameter at least about 50% larger than the diameter of similar bands previously employed and ranges from 1.4 to 2.2 mm. The length or thickness of the band is at least 50% greater than the internal diameter of the band; and, in a preferred embodiment, the internal diameter of the band at both ends is about 0.2 to 0.6 mm. smaller than the internal diameter at the mid portion of the band. Thus, in a preferred embodiment, the internal diameter of the tube at its mid portion is 1.8-2.2 mm, at both ends is 1.4 to 1.8 mm, and the length of the band is 2 to 3.5 mm.