15 and 50 ml test tube holder

thingiverse

Lightweight Tube Rack for Convenient Storage and Transport. This innovative design holds 15 ml or 50 ml conical tubes, as well as 20 mm diameter glass tubes, with a brief assembly required to secure them in place. One major advantage of this rack is that it eliminates the need for supports during printing, allowing for a smoother post-printing process (please refer to our post-printing notes for more details). Originally created to address the issue of bulky Nalgene tube holders, which can be cumbersome to carry around when handling small numbers of tubes.