DeepCool Z3 PRO is a grey thermal paste for the interface between a processor or graphics chip and its cooler, supplied as a 1.5 g syringe. It fills the microscopic gaps between the heat spreader and the cooler base so that heat moves into the heatsink efficiently, and is used when fitting a new CPU cooler, re-pasting an older desktop or laptop, or servicing a graphics card. DeepCool rates it at 4 W/(m·K) thermal conductivity with a specific gravity of 2.3 g/cm³ and an operating range of -50 to +220 degrees C. The compound is electrically non-conductive, so a small overspill onto surrounding components will not cause a short, and DeepCool describes the formula as non-curing and non-corrosive, with a density suited to the polished bases of most CPU coolers. It is a step up from the original DeepCool Z3 (rated above 3.5 W/(m·K)). The syringe weighs about 5.8 g in total, with 1.5 g of paste, which is enough for several typical desktop CPU applications. DeepCool part number R-EZ3PRO-G.