Unlike other racks that can obstruct labeling on short 50 mm tubes, the single tier makes it ideal to view labels at a glance. The second tier can be added for taller tubes - up to 150 mm - with the same stability and confidence. Easy-to-assemble interchangeable tiers securely connect for “small or tall” applications – it’s like getting two racks in one. When not in use, the optional second tier conveniently snaps and stores under the base. Measures 235 x 114 x 67 mm. Pack of 2.