SW Spiral SPT886 8"x8"x6" Spiral Tee. Spiral pipe is formed from a coil of metal into a rigid steel tube with a 4-ply spiral lockseam. The SW Spiral SPT886 8"x8"x6" Spiral Tee features a smooth interior that delivers air seamlessly and a grooved seam for extreme resistance to crushing. This Tee is the most efficient way of connecting multiple lines together with a single fitting.