At the gym six months ago they introduced my karate class to some new equipment to help our fitness. I was really shocked and surprised when my coach wheeled in a giant tractor tyre for us to flip. I asked him were he got it and he said he got it from gracie bjj australia for free. I was really impressed with how heavy the tyre was and how much strength and conditioning was required for me to lift it. I think it will be a valuable training tool for my class. That night all the students gave it a go and comment on how hard it was.