this one for leaving at your house – will secure everything as long enough 1.5 m and will clearly be a detterent… that is all you will get for £25 a detterent.
WAY too heavy to even think about as portable it is a few kg in weight.
To get an uncroppable chain you will be spending hundreds and an uncropable D lock eg New York about £50 -70. I would get this for portability
I have one of those and use it almost daily when working. It is heavy, i looks butch and nobody tried to pick it yet – looks too much for a local chav.
A cheaper option would be to get a motorcycle chain – I bought one ata bike sow for a tenner and the Oxford looks puny in comparison.