Installed in the same manner as flax packing. GFO is a fiber packing that is 4 times more thermally conductive than flax. It needs virtually no sea water for lubrication or cooling and because it doesn't swell or shrink, leakage is controlled and kept to an absolute minimun.
In fact you'll notice that your bilge is dry and cleaner, because this remarkable packing hardly ever drips. It's so conformable and flexible that it will solve most perpetual problem leakers, too.
The proper packing size is determined by measuring the I.D, of the stuffing box (hollow nut) and the O.D. of the shaft.