The standard GT/GTO/GTT Greenspeed HEADREST, designed for the 3/4″ Cro Mo seat tubes can also be used with the Magnum 1″ alloy seat tubes with the addition of two sizing sleeves available from Greenspeed dealers. When fitting the head rest, make sure that threads of the fixing bolt are greased, and that the fixing wedge is inside the split sleeve. The head rest is adjustable both up and down and fore and aft, and is designed to fit the nape of your neck, so that it does not interfere with a helmet. Plus they have have flag mounts, as the arms block the seat flag mounts. New Magnum specific headrests, with larger diameter alloy tubing were be available from June, 2012.