Harken 1603 Midrange Stand-Up Spring - 64mm x 35mm

Does what it says on the tin.

Got this to replace old one which popped overboard when the shackle went. Rooster are probably right to say you need this one for a Laser rather than the smaller (and cheaper) springs on offer which I was tempted to buy and it certainly does the job. Used the double zip-tie trick to squeeze it down to fit the shackle which certainly helps. Delivered in two days which is pretty good.