The Picarelli base tube is chrome-plated brass. The plastic is molded PVC. All parts are unaffected by chemicals used in the industry. All parts are interchangeable and replaceable. The piston is designed to "clean sweep" the inside of the gun with each plunge. This means that to clean for a change of color, simply wipe off the outside and the end with a paper towel. No tools required to disassemble for occasional thorough cleaning. Save money with no ink spillage!! Saves time - will transfer one pint of ink in seconds. BEST VALUE OF ALL - NO MESSY WORK AREA!!