Cage Sizing
Note that for long term wear, we suggest the sizes recommended by the sizing guides on our product pages. Proper sizing is important to have extra space for adjustment and cleaning. Downsizing will make this more difficult or impossible. We recommend people start with Standard width cages, and only try the narrow or wide cages if you've tried our standard cages, or other cages in the past, and found that the fit was not satisfactory.

| Cage Size | A (Length) |
| Nub | 36mm |
| X-Small | 45mm |
| SS | 65mm |
| Small | 70mm |
| Medium | 80mm |
| Large | 93mm |
| Cage Width | B (Entrance Diameter) |
| Standard | 37mm |
| Wide | 41mm |
| Narrow | 33mm |
Ring Sizing
Our ring sizes are measured in mm of internal diameter. Ring sizing is very difficult from measurement alone. The most reliable way to get a working ring size is trial and error. In general, 42.5mm and 55mm are very small and very large respectively. If you haven't had any previous cages, we recommend starting with a 47.5 ring, and adjusting from there, or buying multiple rings (45, 47.5, 50) to figure out the best fit.
Ring gap is the distance between the cage and the ring.
| Â Ring Size | Ring Gap (Standard) | Narrow | Wide |
| 42.5 | 8.5mm | 8.5mm | 7mm |
| 45 | 8.8mm | 10mm | 7.2mm |
| 47 | 9.5mm | 11.5mm | 7.7mm |
| 50 | 11.5mm | 12.5mm | 8.2mm |
| 52.5 | 13mm | 14mm | 10mm |
| 55 | 14mm | 16.5mm | 11.2mm |