Valve Shield is a dual purpose lead replacement additive formulated for vehicles that were originally designed to run on leaded fuel and vehicles that run on LPG, CNG, Petrol & Petrol/LPG (dual fuel systems). It protects engines manufactured to run on leaded fuel and LPG against valve seat recession (VSR) whilst protecting them from intake deposit build up. It is also suitable as an Upper Cylinder Lubricant (UCL) in LPG or dual fuel system fitted with LPG dripper systems. NOTE: Replaces Upper Cylinder and LPG Lubricant