RED Paddle board windsurfing mast foot knuckle joint

The knuckle UJ is a universal windsurfing attachment ideal for an inflatable SUP windsurfing board, which works with any size rig, although we recommend for our boards using any sail size 5.5m and below. We highly advise going for a knuckle mast base, as due to its design it puts less stress through the board, making it the best one to use for an inflatable windsurfing SUP.  There is an m8 thread that screws into your inflatable board ( if it has a place for this) . The top of the mast foot is a euro pin to take a euro pin mast extension , ( not included)