11cm - $15.95 12cm - $15.95 13.5cm - $15.95 Qty. 1 2 3 4 5 6 7 8 9 10 Add to Cart AFI Glass 18mm to 18mm Stem Various sizes - is currently on backorder. You may still purchase now though and we'll ship as soon as more become available. Diffuser down stem Available in 11cm/12cm/13.5cm from the top of the lower grind. 18mm/18mm sg