Its an holder for an USB Charger with an integrated voltmeter and a KCD1 switch (round version).You need two M5x25mm Screws.
USB-Charger: https://www.amazon.de/30W-USB-Steckdose-12V-Auto-Schwarz/dp/B08BBZ23MB/258-7355523-0833438?pd_rd_w=tP5as&content-id=amzn1.sym.d95c9896-f01c-4d4b-b9f5-65a13021c181&pf_rd_p=d95c9896-f01c-4d4b-b9f5-65a13021c181&pf_rd_r=TR57AH1T22C7QS5CD3A6&pd_rd_wg=9EA3V&pd_rd_r=4f6a40a5-6648-42cd-8e15-166f4d06c8db&pd_rd_i=B08BBZ23MB&psc=1
The author marked this model as their own original creation. Imported from Thingiverse.