The Utillian 420/421 Mouthpiece is identical to the original mouthpiece received with the Utillian 420/421. It comes with the glass mouthpiece itself, the metal heatsink which screws into the unit and the silicone heat shield. It's a perfect replacement if you have lost or damaged your original Utillian 420/421 Mouthpiece. For optimal results, it's generally recommended to clean your glass mouthpiece every 2 weeks. Compatibility Utillian 420/421 Package Contents 1x Utillian 420/421 Mouthpiece w/ Heat Shield Cleaning Instructions: Remove glass mouthpiece from your vaporizer Discard any loose materials that may remain Allow the glass mouthpiece to soak in diluted ZEUS purify cleaning solution for at least 30 minutes. Use ZEUS Bristle Pipe Cleaners to remove any remaining material or build up. Rinse thoroughly with water and allow to fully dry before reassembly.