Turn your manual stringing machine into a constant-pull machine with the Tourna Ennox Electronic Tension Head! This tension head mounts to a manual crank or drop weight stringing machine. Fine-tune your settings with up to three pull speeds and prestretch levels. Fast, quiet and functional, the Tourna Ennox Electronic Tension Head lets you string with pro-level precision! Key Features: Fits on standard crank rails or drop weight bases Glide to activate gripper lets you grip the strong with one motion Precise chain-driven motor delivers consistent pulls without the noise Large display with premium resolution for easy visibility Three speeds: fast, medium and low Three prestretch levels: 10%, 15% and 20% Prestretch duration: 0.1 sec to 1 sec Knot function: 5 - 20% Memory: Three preset tension settings to quickly switch between setups Tension increments to 5 lbs KG/LB