K&N Gold series oil filters meet and exceed the original OEM and QS900 oil filter specifications. TUV endorsed and TUV factory production monitored. The latest technology synthetic blend filter media stops more dirt, yet allows more oil flow with less pressure drop. Designed for both petroleum and the latest synthetic motor oils. Built-in check valve prevents oil drain back and dry starts and they also feature a pressure relief valve. The 17mm nut makes removing and installing a snap even in tight applications and it also features a pre drilled hole through it for race bike safety wiring. Designed for street or racing applications and is unaffected by racing fuels. The spin on type oil filters have a outer shell is that is 50% thicker and a much stronger inner core as well as a heavy duty base plate with double rolled seal and high quality o-ring.