The RZ Mk.II Sonic Screwdriver features many improvements over the original design. The primary housing is constructed from the same material as the outer plasmic shell of a TARDIS and thus offers exceptional durability. For power the RZ Mk.2 utilizes a fragment of a black hole, ensuring a continuous supply of energy. Stabilizer pylons fitted to the emitter head boost performance and fine control considerably. Of note is the inclusion of a red setting in this design.
The less "in-universe" description:
So here it is, my third custom sonic screwdriver. I actually bought parts for this, though much of what I used did wind up being found junk. The bottom assembly detaches for easy battery replacement, which is something my first two are incapable of, unfortunately.
Unlike the River Song Future Sonic, mine has both colours of "emitter" built in. They are both brighter than seen here, but under flash they just appear a bit dimmer.