In accordance with ISO 6789:2017, Armeg recommends that after 5000 uses or 12 months (whichever comes sooner) your Switch-Blade handle is checked and re-calibrated. Set also includes the VDE handle which is perfect for versatility and convenience and VDE T-Handle which provides more powerful leverage for high torque loosening and tightening. Set includes new hex size VDE blades. All handles and blades are 1000V VDE rated, GS Approved and comply with IEC 60900 for confidence and safety when working on live installations., Weight: 3.6596735492 Pounds, Manufacturer: Armeg