Abstract: A manual two part automobile seat belt tightener which conveniently assembles and disassembles to permit intermediate attachment to a seat belt without the need to pass any of the seat belt buckle parts through the tightening mechanism. The tightener mechanism includes a non-circular bifurcated pin or reel and a complimentary non-circular aperture in the tightener frame to assure that the pin or reel cannot be rotated until the pin or reel is fully inserted in the frame. In particular, in attaching the tightener to an intermediate portion of an automobile seat belt, the tightener ratcheting mechanism cannot be rotated unless the bifurcated pin or reel is fully inserted into the ratcheting mechanism. An additional advantage to the new tightener is the significantly simple and sturdy construction that can make use of a conventional hexagonal ratchet wrench mechanism in the novel combination.