Grex Cup (50 cc)Grex Side Cup (50 cc) 50mL Side Cup For Genesis. XS, XSi, XT, & Tritium. TS The Grex Cup (50 cc) is a must have accessory for any artist or hobbyist who uses the Genesis. XS, XSi, XT, or Tritium. TS airbrush models. This 50mL side gravity feed cup is designed to provide a secure fit onto the airbrush, ensuring that your paint stays in place and doesn't spill. With its adjustable feature, this cup can be positioned at any angle on the airbrush,