Questions about R&M Multimedia box

Yes, is compatible with Feller EdizioDue. Also supplied with standard Feller mounting frame. Fastening is arranged horizontally (when orientated as shown in the product image). Can therefore be mounted in a frame of 2 without any problems

The R&M flush-mounted multimedia socket 3-hole 11dB (R170814) is not specifically designed for fibre optic cables, but rather for connecting various media such as telephone, internet and audio/video. There is no specific indication that it is suitable for fibre optic cables.

It's low voltage, no risk to children

The question should be asked directly to cablecom.