Cheers chaps, useful info on here.
They’re for a hoist which lifts a wheelchair in and out of a car, to connect from the karabiners on the hoist round a part of the frame and back up – whatever I use has to be strong enough (as mentioned probably only up to around 20kg on each side), resistant to abrasion and catching on bits of the frame, thin enough to easily be dropped between the frame and the wheels and looped back round and with permanent loops rather than knots which could loosen over time.
Rusty, that type of thing is perfect in terms of function, but not really thin and flexible enough.
I’ll have another think, but good info on here thanks.
Edit – total length from eye to eye needs to be around 50cm.