Fits 6 15x100mm glass test tubes.
Printed at 0.2mm layer height at 25% infill PLA.
The tube fit should be tight so it doesn't wiggle.
I bought the tubes off Amazon https://www.amazon.com/dp/B07D9HJ4XW?psc=1&ref=ppx_yo2ov_dt_b_product_details
The author marked this model as their own original creation.