4" Vent - Typically used on USP 8 Cox FootStop & Stern Sectional 4's.
5" Vent - Standard used in all SP HUDSON's Singles through to Eights, USP Singles, Pair/Doubles & Fours. Now with improved seal & 1/4 turn lock.
6" Vent - USP 8's Now with improved seal & 1/4 turn lock.
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