Abstract: At least one pair of opposed, congruent, transversely curved, longitudinally consistent, surfaces each presented by one of two portions hinged together at one end intended to traverse the stem of a balloon are brought into a close spaced apart parallel disposition tensioned between a pinion on one end and catch on the other. The spacing compresses the two walls of the stem of a conventional balloon together providing a tight seal that can be released manually for reuse if desired. An oval perimeter to at least one of the two portions, with the pinion and catch defining the longitudinal axis, is suggested including a band defining an aperture for securing a tether is suggested. Use of two adjacent pairs of opposed, congruent, transversely curved, longitudinally consistent, surfaces is also suggested to yield a rounded shape to avoid potential skin abrasion in manipulation or in being hit by a water filled balloon.