This is a simple bottle cage for bicycle frames with a bottle cage mount. Screws with a head up to 6.5mm tall can be used with this.
Depending on the bottles you're using, there are two files, one with a 65mm bottle diameter and one with a 70mm diameter. The picture shown is a 65mm.
The bottle cage was intended to snugly hold a 20oz Hydro Flask Wide Mouth tumbler. It should also hold a 24oz since it has the same diameter. But I don't own one so haven't tested it ;)