From the Loftsmith community

Tube rack base (2×6)

Gives twelve test tubes a steady place to stand instead of rolling around the bench. They sit in two rows of six, each in its own shallow socket. A small catch post at each end and a channel along the sides help it link up with other pieces. Change the tube diameter to match yours.

1 part · 68 g · 165 × 72 × 38 mm