This is a holder for the Shopify tap-and-chip POS reader. 

Due to the tolerances of various filaments and machines, this is purposefully designed a little loose to make sure it's easy to remove the reader should it be needed. I personally put a half a business card under the reader, which makes it sit tight, but remains easily removable. 

You can charge the reader in the stand. If using outside at sales in a lot of UV, I'd recommend PETG or ASA.