Unlike other rests that drop-away because of inertia, or vibration, the ULTRA REST relies on the velocity of the forward movement, via the Timing Cord attached to the bows downward buss cable, to initiate the launcher to drop. VDT assures that the ULTRA-REST remains in the cocked position even on a slow let down and will only drop-away if the bow is fired. Keep your arrow in total containment whether you're stalking, drawing, or during a slow let-down