4ml - $4.95 5.5ml - $5.95 Qty. 1 2 3 4 5 6 7 8 9 10 Add to Cart GeekVape Cerberus Replacement Glass Tube - is currently on backorder. You may still purchase now though and we'll ship as soon as more become available. Replacement glass tube to suit the GeekVape Cerberus tank. Available in 4ml & 5.5ml