Onepiece Lab Wooden Colorimetric Tube Rack Easy to store: compact, simple design keeps workspaces tidy between steps and experiments. Flexible compatibility: designed to hold colorimetric test tubes in standard sizes 10 ml, 25 ml, 50 ml, and 100 ml. Configurable holes: available in 6hole and 12hole configurations to match your workflow and tube count. Solid material: made from wood for durability and repeat use in everyday lab tasks. Type and purpose: colorimetric tube rack intended to securely organize colorimetric tubes during assays and demonstrations. Stability and organization: provides upright support to reduce tipping and keep tubes organized by size or sample. Practical use scenarios: In the laboratory during colorimetric assays to organize and access tubes quickly. In classroom or teaching labs to display multiple tubes for demonstrations and student observation. In sample processing or quality control to keep tubes orderly during analysis and comparisons.