This is 25m of 4mm stranded cable for use with ONLY
This replacement cable is NOT intended to be used to extend an existing cable. It is sold soley for the reason of people who wish to move the location of existing cable to another location, yet the original cable is dented where wire rope clamps had been placed which would cause damage to the trolley wheels.
If you have damaged the cable in any other way, it is very likey to happen again with this direct replacement, and usually means that you have exceed the breaking weight or extended the length of the cable. Ignoring the manufactures restrictions is very dangerous and should not be deviated from. You should be looking at buying a higher spec model which will take the weight and run without fault over the length of the ride.