This is an extremely accurate fan-made replica of the TARDIS key as used in the 1996 Doctor Who TV movie, featuring Paul McGann as the Eighth Doctor.
The key prop used in the film was an official TARDIS key replica available at the time from 800-Trekker, a now-long-defunct scifi memorabilia catalog, under license from the BBC in the early 1990s. The 800-Trekker key was a unique design largely based on TARDIS keys used on-screen by the Third and Fourth Doctors in the 1970s, but with many noticeable differences from those TV props. Rather than design a new TARDIS key for the 1996 film, the film's prop department just bought a supply of those keys from 800-Trekker and made them the canonical key design used by the Seventh and Eighth Doctors in their movie.
The newly-canonical 800-Trekker keys became very popular with fans, but had already been out of production and in limited supply by the film's release. They were also made of a very soft pewter which scratched and bent easily, so very few good copies of the Trekker key remain in circulation today. I happen to own one of the Trekker keys, ordered myself from the catalog around 20 years ago. Armed with calipers, 3D software, and a desire to replace my prop (which has begun to show noticeable wear, despite my best efforts to preserve it) with something more durable, I painstakingly recreated this key based on it.
My key does have some infinitesimal differences from the prop. Perfect circles on my version may have been slightly elliptical on the original, and my version lacks the mold lines present along the edges of the original. Wherever it came down to a choice between duplicating imperfections in the original's casting process versus using the exact geometric nature of 3D design and printing to its fullest, I've chosen the more clean-looking route.
So, here's what I feel is the neatest replica of the Eighth Doctor key you can find! Please share, enjoy, and have fun with it.
Please note that if you plan to put this on a necklace, keychain, or similar, the hole in the key is only 3mm in diameter. For most chains, this means you'll have to add a small wire loop to the hole which the chain can fit through. This was done on the original Trekker keys, and such a loop appears on the film prop. You can get them from craft supply shops, or take one from an old keychain or pendant.
If you'd like to buy this key printed in metal (or other interesting materials) on high-res industrial-grade equipment, following this link to my Shapeways shop and buying it there would be very cool of you. Examples of Shapeways metal prints can be seen in the photos here.