A pair of cam-buckles properly disposed in a back-to-back manner may be slid along an anchoring strap passed through it and yet reliably kept in place to accommodate loads depending from it regardless of the direction the load is tethered from without danger of slippage along the strap. While this arrangement may be used in a general way for various tasks, it has particularly beneficial application for tethered physical exercise activities. With it, the anchoring strap may be vertically secured around a door and the paired buckles may be moved to any point-high or low-upon the strap, thereby providing variation in tethering direction.