I created this Suction Hygrometer Holder to hold (using two 20mm suction cups) the common rectangular hygrometer (humidity / temperature sensor) that is available from dozens of vendors on Amazon, AliExpress, etc. It is designed to be attached to the inside of a filament storage container or printer enclosure on a transparent wall or door for easy viewing from the outside.

This holder is designed for hygrometers with body dimensions specified as 48mm wide by 28mm high. My hygrometers (from two different suppliers) are actually closer to 46mm by 26mm, so I sized the opening to fit these; let me know if you have hygrometers that actually match the specified sizes, and I'll make a version with a slightly larger opening. A STEP file is included in case you'd like to modify the design yourself.

The openings to attach the suction cups are designed for "Shapenty 20mm Diameter Small Clear PVC Plastic Suction Cups Without Hooks" from Amazon (U.S.) at: https://www.amazon.com/gp/product/B06X934SFK, but it appears that many other available options in 18mm or 20mm sizes should work as well. Please take a look at the attached photos for clarity.

The provided STL files are intended to be printed in PETG and do not require supports.

PrusaSlicer 3MF files are provided for Prusament PETG and G-code files are provided for the Original Prusa MK4 - for one holder as well as for six holders.

The Suction Hygrometer Holders seen in the photos were printed on an Original Prusa MK4 in Prusament Orange PETG with a 0.4mm nozzle using Input Shaper at 0.2mm SPEED layer height with a 10% gyroid infill and Concentric top and bottom fill pattern.

Be sure to check out my other designs - including a diverse collection of household accessories and 3D printing tools - on Printables at https://www.printables.com/@PhilCaruso_661446/models