Have 2 red Schroth Rallye 4 harnesses for sale. I purchased them new for $180/each, and only used them for 3 HPDE weekends. Now that I have a half cage and race seats w/6pts I have no use for these anymore. I am selling them $250 for the pair (preferred), or $150 each. (Those considering buying only one harness should note that many clubs require equal restraints for the driver and passenger)
They are DOT approved, 4pt harnesses with asm technology (anti-submarining). Video on that here:
Great for AutoX, HPDEs, and track days because they keep you firmly planted in the seat, which means you aren't sliding around in your seat (reduces the fatigue on your arms that comes from trying to support yourself in the turns), and you feel more connected to the car.
Schroth belts are usually the only type of 4pt harnesses allowed for track days/HPDEs because they have the ASM technology. I've gone with several different clubs (BMW CCA, PCA, Trackdaze, Trackclub USA, Rezoom Motorsports) and they all allow the Rallye 4 harness. Also, unlike race harnesses, Schroth doesn't have expiration dates for the Rallye harnesses. HMS recommends changing them every 7-10 years.