The ‘Skeleton Saturns’ were the final models to be produced in Japan (and hence the world), and they were the only non-standard models brought to other regions.
They are a valuable collector’s item.
The unique feature that provides their name are their see-through body and matching controllers.
Models & Variants:
HST-0020/HST-0021: These two models were both translucent smoky grey, with “This is Cool” printed on the CD drive lid and the controllers.
The second model, HST-021, was the only one released outside of Japan. Approximately 30,000 units for Japan and 50,000 for the the rest of the world produced.
HST-0021 was released in Japan on 4 April 1998.
HST-0022: This model was a promotional tie-in with ASCII's popular Derby Stallion horse racing simulation franchise; it came with stickers for the game and says something about the game on the box. The console differs in the hue of its transparent case and also does not have the line “This is Cool” printed anywhere on it.
Approximately 20,000 were produced for Japan and mass exported to the other regions.
After supplies of the skeleton Saturn previously being limited, this was quickly bought in bulk by exporters and for a time was easier to find outside Japan than inside. This model was released in Japan on 25 March 1999.