Every builder needs an Allen key in his arsenal. We sell high-quality 8mm Allen keys. These are made according to the DIN 911 standard. These are perfect for installing EK-ACF Fittings 10/13 and 10/6 sizes for your personal water-cooled computer. Allen key 8mm, according to DIN 911 standard. perfect for installing EK-ACF Fittings 10/13 and 10/16 size.