You can sync 2x45000s, 2x95000s or 1×95000 and 1×45000 via MIDI Clock.

When syncing these loopers to MIDI Clock it is always best to engage Quantize mode. Quantize mode forces the loopers to create loops that are exact bar lengths. Not only does each looper’s tempo need to be running at the same tempo but they need to cycle the loops at matching boundaries (even if the loop lengths are multiples of each other). If Quantize is not enabled than the loop lengths will be off and when the loops cycle the audio will slip so they don’t sound in sync, even though they are running at the same tempo.

Having said this you can sync up two units with just MIDI Clock and not enable Quantize. In this case, you can make new loops with matching tempos but non-matching loop lengths. The 95000 is better at working with just MIDI Clock than the 45000. The 45000 needs the MIDI Start command whereas the 95000 has an EXT. CLOCK mode that does not require MIDI Start.

If using the 45000 with Quantize enabled, it will always use a Count-In. On the 95000, you can enable Quantize but turn off the Count-In.