The official Syro gear list mentions the Micmix Dynaflanger.

According to Mk-guitar's section "Mark Knopfler's Guitar Effects," Mark Knopfler used the MicMix Dynaflanger Model 265 during his tours with Dire Straits in 1985 and 1986.

Mentioned in this February 1983 Guitar Player interview.

Q:What kind of effects did you take out on the road with you on the last tour?

FZ:I took three MXR Digital Delays -- two with minimum memory storage, and one with tons of it. I also used two MicMix Dynaflangers. I didn't have any fuzztones or octave dividers. I used three different amps: a Marshall 100-watt, a Carvin, and an Acoustic -- and each was interfaced with a different digital delay. So I could store three different signals and get some weird sounds. For instance, you take your whammy bar and get some terrible tweezed noise, and store that. Then it would come out of the right, and another one would come out of the middie, and a third one would come out of the left one, and you could play over the top of it all. I've got a lot of recordings of that from the tour, and it's really an ungodly sound.

(...) Q:On "No Not Now" [Drowning Witch] there's an extremely distinctive bass line. Did you write it?

FZ:I just made it up. The bass part was done like this: Arthur Barrow came in to play bass and, bar by bar, I would hum it to him. We'd play it, and he'd go as far as he could, and then he'd make a mistake, and then I'd show him the next part, and then we'd punch him in. And that's how it was done: like eight bars at a time. It's a wonderful bass line.

Q:The entire album's bass lines are played up quite a bit. Did you purposely spotlight the bass on the album?

FZ:I think that's a result of mixing on the 4311s -- it just gets accentuated. It's up in the mix, but not to a radical extreme for a comfortable listening level. I like bass lines. They're good, because for people who don't understand what's going on in the rest of the song, there's always the bass line.

Q:What kind of effects did you use on the guitar throughout the album?

FZ:I used a MicMix Dynaflanger and Aphex compressors. The signal is compressed after the hanging. And the hanger is set to follow the envelope of the high-frequency decay, rather than the amplitude envelope.

Q:What kind of difference would that make?

FZ:It gives a totally different sound. It makes a more pillowy effect from that particular device.

Q:Why would you compress the signal after the flanger?

FZ:Well, for one thing, you would compress it if you didn't want more hanger cycle. And hangers boost certain frequencies in the midrange that go hog-wild if you don't control them. So we started off just to control those frequencies, and then by cranking that Aphex compressor to some ridiculous extent we got this other kluge sound.