A keelstepped mast must be securely fixed in the deckring without any movement. This in order to prevent damages to the mast and to obtain the required integrity of the complete rig system. The mast must have an even curvature (convex forward) right down to the mast heel which is achieved by a correct mast heel location and orientation of the mast in the the deckring. 

The quadrilateral rubber mast wedges that we provide are designed for Seldén E-sections and associated deck rings. For information on what mast wedges to use for your individual mast, go to the Seldén website and Yacht Catalogue, Version 6, page 67. 

When you have stepped your mast and are ready to get the rubber wedges in place - do like this:

Locate the aft wedge/wedges in the deckring and secure with a piece of tape around the mast.
Tie two lines to the mast and lead the lines to the primary winches. Tighten up equally on each side to fit the forward wedge. Wet the rubber with water/soap and it will slide down easier.