The breaking load of the M12 is rated at 2500kg, so there will be 6, and 3 ratchet straps rated at 5000kg. So yes I feel happy with this, they look a lot more robust than the standard tie down points already in the van, I don't really see that it will be much different to having a tank bolted down. I will still have the tank around the frame, just the straps will hold it all down rather than permanent bolts.