Flexitime Xtreme Heavy 50 ml Econo 12/Bx by Kulzer SKU 959-66019684 123 $239.99 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Sold out Flexitime Xtreme Heavy Tray, bulk cartride refill: 12 - 50 mL Cartridges and 36 MIXPAC Mixing Tips.