This is a part that holds this small voltmeters:
[https://s.click.aliexpress.com/e/_dZBPU7C](https://s.click.aliexpress.com/e/_dZBPU7C)
(Affiliate link)

I used it to modify a lithium battery charger, you can see how to in this video:
 

Designed in Onshape, here is the link if you want to download and/or modify it: [https://cad.onshape.com/documents/8768c1b717ccd29fe46f0c01/w/221ca6c364028027ebae3dd1/e/440dc7ef997b5772999c2db4](https://cad.onshape.com/documents/8768c1b717ccd29fe46f0c01/w/221ca6c364028027ebae3dd1/e/440dc7ef997b5772999c2db4)

Print instructions

Supports not needed.
Designed to be printed topside down.