I have an 18.8mm diffuser/slide combo for sale. The diffuser is roor brand, brand new, and has 16 holes. It measure 4 1/2 inchs and is perfect for any flat bottom glass on glass piece. The slide is also roor, brand new, and is extra large. It has lavender, white and red swirls. Slide has three large glass beads and three small glass beads on the side. The price for this Roor combo is $130 dollars plus 10 dollars for priority shipping/ handling within the USA. Please email me at [email protected] with any questions! Thanks for looking.