The 7.25" Pulsar Propeller Perc Water Pipe has a unique rotating perc that spins faster the harder you hit! This perc generates finely diffused bubbles for cooler, smoother hits. Other features include scientific-grade glass with purple highlights, a 14mm female joint for superior glass-on-glass connections (and easy customization), a 14mm male herb slide, a bent-neck mouthpiece to keep the flame out of your face, and a splash guard dome to keep the water where it should be- not in your mouth!