TPU Spacer for Insulin Vial Saver - Fiasp

I printed Maanprints tpu insulin vial saver but found that for my Fiasp vials the inside was slightly too tall. I made this 4mm spacer. I found using this diameter and printing out some different heights worked great. Maybe it's just my printer but of the 4 I printed out I ended up needing 5mm, 6mm x2, and a 7mm circle to get the vials to fit snugly. I would recommend changing the z height in your slicer and printing some 2mm and 4mm discs to find the right fit. The one here is 4mm. 

added spacer to make the fit with other insulin vials tight.