Not seen these specific one's but I do have similar reservations to above about such items. If you do fit them under what conditions? Drive until stuck in a drift then expect to fit them? Drive on a snowy road and trash them and the car as soon as you hit clear roads and given the Zed is useless in snow anyway. Carry heavier chains that will do the job better (and I do this in mountains competitions in big Jeeps and they are horrible to fit at -10c in snow and then remove to be legal on clear roads
Personally I don't waste time with them on the likes of the Zed and i I felt the need to have the Zed in all weathers and road conditions would opt for winter tyres and be safe and secure. Same debate is ongoing on the Jag forums where they are equally useless in snow...