Netgear GS308EP PoE 8 port switch
I have successfully powered 3 RPIs with this device, but it should have no issue powering a full 7 (with one port for uplink).
In order to use this you will require PoE hat for your RPIs. I have used the official PoE v2 hat https://thepihut.com/products/raspberry-pi-poe-plus-hat. But any would probably do.
IMPORTANT: I have yet to discover how to make the cooling fan work on this device. It is challenging because we have used MAAS to install a generic version of Ubuntu without specific RPI device support. It is also not possible to use a passive cooling case with the hat in place. For this reason I suggest that you provide some external cooling for a cluster built this way e.g.