The Pulsar Plug is a set of two cleaning plugs that have a tapered design to fit the mouthpiece and joint on most 14 & 19mm water pipes. The Plug is made with 100% BPA free and FDA food grade silicone. The two pieces nest together for easy storage. Dishwasher safe and heat resistant up to 445F. Fits mouthpiece openings from 35mm to 60mm.