Forespar 50/50 Carbon / Aluminum Line Control Whisker Poles Sailboat Hardware & Rigging_Sailboat Steering The rivets are hollow and

The rivets are hollow and can be used to fasten the blocks with screws

That being said

and spinnaker control applications on one-design classes and sport boats up to 33 feet as well as control line applications on larger boats

Flared cheeks prevent chafe on the halyards

Ronstan drain plugs are fitted with watertight seal and retaining legs to prevent accidental loss

Forespar 50/50 Carbon / Aluminum Line Control Whisker Poles Sailboat Hardware & Rigging_Sailboat Steering The rivets are hollow andThese Line Control Whisker poles offer just the right blend of aluminum and carbon structures to provide racing or cruising sailor weight and cost savings. They have the strength and weight savings of carbon on the inner tube and the abrasion resistance, durability, and cost savings of aluminum on the outer tube. They also feature Forespar's exclusive "Ultra" end fittings (UTS socket inboard and UTR trigger outboard) for further weight reduction and