The spacer sleeves allow the comfortable installation of a radiator on top of a PC case without having to machine a large opening into the case. Only 4 holes with a diameter of 4mm must be drilled, the M3 or M4 screws for installation of the radiator can the be pushed through from inside of the case and inserted in the radiator’s threads. These cool sleeves ensure a unique appearance and a space of approx. 34mm between the radiator and the case. This allows optimal Airflow through the radiator from below. Technical details: Colour: Black Material: Plastic Inner diameter: 4mm Outer diameter: 8mm Length: 35mmm Extent of delivery: 1x Spacer sleeve 4,2 x 8 x 35mm RAL 9005 (black) Please note: No screws included