I know they come stock on the Gas Gas's but I probably am the only one in the US with any experience with Messico on other brands. I've rode in Italy and used them on KTM, Husqvarna and Yamaha (all 125's) in my experience they are super strong, top end orienated, rev-forever pipes. They are for wide open fast GP style mx tracks. This is my experience. I love them, but the one's I've ran are not really easy to use. But they make two different pipes for each model, and I am sure the enduro pipes are great at that type of riding. Personally I think they kill all the American comanies products.