The Allen A5266 Mainsheet Jammer is
designed to prevent the sheet from wrapping round the block resulting in
extra control for faster, smoother tacks and gybes. By moving the block
outward from the swivel and angling it away from the cleat the mainsheet
system creates turning force on the block and jammer meaning the cleat
will always be forced to point away from the boom and towards the helm.
ASS version includes the assembled 60mm