For feeding sail slides
Entry into spring-loaded gate
When reefing, the sail slides pass through the closed gate down to the boom, holding the sail in place and facilitating fast and safe reefing.
Large size for: E138, E155, E170, E177, E189, E206, E224, E237, E274 mast sections.
Small size for: E122, E130, D109, D121 mast sections.