This Victron Product and leads was removed from my VW T5 van that had a leisure battery fitted to charge from the main battery
Victron Cyrix-ct 12/24V-120A Battery Combiner
This Kit is for adding a 2nd or 3rd battery system in your car or camper van. It utilises the battery positive from your standard battery to keep all your batteries charged using the engine's electrical system, but isolates the starting battery when charging ceases so you never get stranded.
Also comes with 10mm² Leisure Battery Red/Black lead set cable set 75amp Rated +M5/6 ring crimps
4x used cut lengths of approximately 400mm and 200mm
Approximately 6.4mm outside diameter
70 amp tri rated wire 10mm2 wire gauge with ring terminal crimped on each end with insulating heatshrink(s) as shown in picture with M5 crimp hole/stud size.
There is also clamps on both the Positive and negative cables for leisure battery connection
These cables are used and were stripped from my camper van that I have broken up for parts