These shoe rack extensions help add an addional ~40mm or 1.5 inches in height between the shelves. I created these so I can store my cereal box containers storing my filament in an upright position. Extensions are pretty snug on both ends when installed so they shouldn't pop off by themselves. 

0.4mm Nozzle

4 Walls

25% Infill

No Support needed (female end on plate)

5mm brim

Archimedean walls

Print 4 per shelf - about 1.5hrs to print set of 4

I installed onto the top of the vertical bar in all 4 corners first, then installed the side pieces that goes above it.

Here is the shoe rack the extensions are used for. Pretty budget friendly. (Not an affiliate link)

https://www.amazon.com/dp/B09Q678QVP?psc=1&ref=ppx_yo2ov_dt_b_product_details

Lower shelves have alternating cross bars left off during assembly to stagger the unboxed filament rolls. Extensions were not installed on these levels.

These are the cereal containers that I have. (Not an affiliate link)

https://www.amazon.com/gp/product/B08JQ9P5L6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

First upload on Makerworld so let me know if you have any questions!

Mahalos