Prusa Mini Base leg extension

The legs for the MINI base designed by Prusa are too short for some spools to fit under the base. These units allow you to raise the base in 15mm increments by stacking multiple pieces. They interlock with each other and with the legs.
I designed this to work with a horizontal spool holder rather than use the built in as some spools that i had were too small of a diameter to fit stabily. My favorite is https://www.thingiverse.com/thing:495821 (shown).
Three heights: 7mm, 15mm, and 25mm all but shortest have insets on the bottom.