This was an electronically-updated twin to the Rolleiflex SL35M. The electro-mechanical shutter's top speed is still 1/1000th but the low end is stretched from ½ second to 4 whole seconds.
The SL35M's CdS meter was also upgraded to a silicon photodiode. A nice unintended-consequence is that this camera takes four 357 cells, which means you can still buy them and not have to deal with adapters or voltage problems.
Rollei built its name and reputation on its pioneering TLR cameras, but they were professional-grade cameras and the pro level went through a huge climate change in the 1960s. In particular, 35mm film and camera quality increased to where they could compete well against larger film formats; the result was a smaller, lighter camera that was more convient for photojournalists and anyone doing field work. It didn't help that the Japanese were churning out high-quality equipment at budget-friendly prices.
So Rollei began to diversify, and one of the things they tried was entering the 35mm market. On the professional tier they created the 2000/3000-series cameras (none of which I have). On the more lucrative but lower-margin amateur and advanced-amateur level (now called pro-sumer), they took a design they acquired when they bought Voigtländer and began the SL35 series of 35mm eye-level SLRs. The first was the German-made SL35 (I don't have one yet), followed by the Singapore-made SL35M, this SL35ME, and finally the SL35E. Bankruptcy and marketing problems put an end to it in the early 1980s.
Purchased from an online auction for $30. Appears to work but it's missing the battery cover on the bottom. It's possible I might be able to bodge up something to make it work electrically; the chances of getting the battery door only are pretty remote. There's also something going on with the self-timer that I haven't figured out yet.
One of Modern Photography magazine's Top Cameras
Camera manual: Orphan Cameras.com