Hygrometer mount for dry box,   used on a Rubbermaid 21 cup / 4 L cereal box. 
EEEKit hygrometer from amazon. 

10mm tall body to allow battery removal with out taking the mount out. 

Stand off's are 3mm high off face to allow mounting with out crushing the meter.

3mm holes for screws. 

Screws used #8 panhead ½" long.

Print material, PLA 

Infill, 15% 

Walls, 2 

Layer height used, 0.2mm 

Printed on a  Anycubic Mega S  using Hello3D PLA  Jungle green. 

Part modeled in FreeCAD 0.21.02