Made in the USA, Lang Tools (4651) Automatic Slack Adjuster Release Tool and Wrench is for use with automatic slack adjusters on Meritor systems. The 4651 includes a fork-end tool, which is for releasing the tensioner button, and the 5/16″ double square offset reversible wrench features an E-Z Grip handle. Release the anti-reverse mechanism without prying and apply more turning power with less fatigue to the hand