I forgot to mention that it’s for two picture frame speakers, in case that’s important.

I’d look at the IKEA site since they make and sell the speakers.

Not seeing it on the US IKEA store site.

Thanks. I called Ikea and all they could come up with was a regular power cable. Nothing about a passthrough cable on the Canadian site either. Since one reference to the cable is on the Sonos support site, I thought I’d try that community.

“The SYMFONISK Picture frame can pass power to a second SYMFONISK Picture frame using a power passthrough cable. Use the passthrough cable to connect the power output on the first Picture frame to the power input on the second Picture frame. When the first Picture frame is plugged in to power, both products will turn on.”

https://support.sonos.com/en-ca/article/set-up-your-symfonisk-speaker

The cable is listed on some EU IKEA sites (saw it on reddit).

Sounds like a PoE or PoE+ link, but without the ‘usual’ data connection - If it is, then any CAT5 (or higher) Ethernet cable should do the trick. That said I’ve never seen it mentioned before in this community - What ports are available to perhaps make the power-connection between the two? - (Ethernet RJ45/USB-C)?

Oh, interesting idea. I hadn’t thought of that.

But

I just had a look at the back of a speaker and noticed that it has an AC-in and an AC-out port. I assume you’d plug one end of the passthrough cable into the AC-out of one speaker and the other into AC-in of the other. Ikea/Sonos isn’t very forthcoming about where to get one, though.

Looks like a fairly standard cable connector, although odd because it’s male. You should be able to find extensions with that connection at pretty much any electronics vendor with a little searching, it isn’t unique to IKEA. 

The AC In is the male connector, the AC Out is female. The connectors do look standard.

I didn’t even know that the Picture Frame speaker had that power-through feature, but I guess it’s helpful to help hide cables. You would think IKEA would stock them though and make them easily accessible in stores where they sell the Frame product. I could not locate one in their online store. I found this on AliExpress … it’s probably not long enough though. It was advertised as a C7/C8 Power "8” Figure Adapter, if that may perhaps help you to find one similar online:

Here’s the UK version: https://www.ikea.com/gb/en/p/foernimma-intermediate-connection-cord-30394699/

Thank you everyone! 
 

I looked up FÖRNIMMA in the Canadian IKEA catalogue and it’s there, but as a the regular power cable. So I bought a 1.5 metre cable off Ali Xpress, which is the longest they had in white. Longer and cheaper than the UK IKEA one, so I hope that it does the trick.