4 Digit digital Tachometer box

This is for housing a digital tachometer like this one (not an affiliate link)
https://www.amazon.com/gp/product/B07X4F1ZHK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

Has a snap on back and a place for a DC power plug in outlet.
Designed for 5/8" x 1/8" rare earth magnets.

Power plug design is these, but can take anything else that is 7-8MM round
https://www.amazon.com/gp/product/B0C3RDNWXY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1