Originally designed to attach a tag (⌀ 33 mm) under the seat of my rowboat, the case is suitable for attaching tags to other flat surfaces such as bench seats, box lids, etc. It has a low, flowing profile to prevent knock-off.

There are two basic models:

1. a simple circular one
2. a narrow one for attaching to narrow surfaces such as planks

The holes take size 3 metric screws, ideally with a conical, recessed head. I print in PETG, which gives the whole thing a very sturdy feel.

The attached 3mf files (and of course also the gcode files) have supports, and I have allowed 0.5 mm of clearance above the height of the tag, so that you don't need to obsess too much about removing the supports interface from the print – with PETG it can be a hassle. There is also a zone with lowered layer height around the top.