K&N (KN-116) Replacement oil filter for Montesa 4RT 4-Stroke. K&N powersports oil filters are "TUV" product endorsed and "TUV" factory production monitored. This means every K&N oil filter is equal to, or will exceed, all OEM specifications. K&N filters contain a modern synthetic filter media, designed for ultimate flow with less pressure drop, yet engineered for outstanding filtration to meet or exceed all OEM specifications. All K&N powersports "spin-on" oil filters feature a heavy-duty metal can with a 17mm nut affixed onto the end that allows for easy installation and removal.