The angle of the intake hole causes water and vapor to spin rapidly and form a powerful centrifugal force. This cools the vapor and makes each hit smoother, and the twin stacked chambers multiply this effect. There's no need to worry about splashback with the Large Circuit Rig, because the sharp bend in the mouthpiece keeps all water inside the rig. This piece includes a 14mm female-jointed domeless nail made of heat tolerant quartz, so all you have to do is add about 0.5" of water and then you can get right down to the fun stuff.