The Optimax Optimist deck collar is made of Delrin to create minimal friction between the sleeve and the collar. The oval inner diameter allows the maximum fore/aft and minimum side play and the tapered inner diameter allows the mast to be raked. 4 countersunk mounting holes. Hole size in deck: 57 mm.
A seperate sleeve is available which is fitted around the mast at deck level and protects the mast from wearing.