A set of harnesses will keep you safe on the street and track. You'll find it easier to drive hard as well, since you won't have to brace yourself. Willans Harnesses are some of the best in the world, with a 5-year certification, soft webbing and top-quality camlock hardware. Watch out, some cheaper harnesses only have a 2-year lifespan.
Harnesses should only be used along with a roll bar that is high enough to go above your head.