Web site: 5250DX Digital Electronic Flash
Manual: Not available online.
Key Features: tilt reflector, modular system
Reasons to Buy: Compact. Can be found pretty cheaply (but the Pentax module adds cost).
Notable Drawbacks: No frills.
This flash is not currently available at large online stores in the US.
A very basic model. You might be able to find this for not much money, although the Pentax module adds about $50.