Looks like a suitable collection of components to do the job well. Nothing too small , fuses in the correct places . I would check that your cable run is actually that short - you may find you have to plonk the relay somewhere unusual to get it all to fit with the 2m kit. I think theres enough wire in the kit, but its cut in maybe less useful lengths. The 4m kit may fit better. The kit is complete , but in the end, what you need is decent earth cable on the leisure battery as supplied, then a length of heavy 12v cable with a fuse near the leisure battery as supplied, then a run of cable from side to side, then the relay , then a length of 12 v cable with a fuse to the other battery. In fact given our 55A alternators, or 38A dynamos, the max current you will see down the wire is probably more like 30A than 100A..
That looks suspiciously like the kit I use from these lot https://simplysplitcharge.co.uk/Split-Charge-Systems if it is the same outfit, then yes, they are fine.
I just installed this one from MVM https://www.megavanmats.com/3m-mvm-split-charge-relay-kit-ready-made slightly cheaper and longer wire. The 3m length is about right. 2m would be tight. It arrived the next day and it is now installed and working.
