Questions about Ubiquiti UniFi SFP+ Twinax cable 3m

Hello, I would like to connect 2 Unifi Switches Pro-24 via fibre with a Unifi Switch Pro-48 redundantly as well as the 2 24Ports with each other. Is this the correct cable: Ubiquiti UniFi SFP+ Twinax cable 3m and is this also available in 5m or what would be the alternative with adapter and fibrecable? and how can I make sure that no loop occurs. Thanks

Hello all.. Can i use this cable to connect between one QNAP TS-1635AX-8G and Netgear XS508M (8 Ports) without problems? Thanks in advance