I have installed these on my daysailer after removing the cheek blocks at the base of the mast. With these cam cleats you can get the halyard tension you want instead of loosing tension tying the halyards off on cleats. The ease in which you release the halyards and drop the sails is also a big plus.
The pivoting base is also great for pulling from different angles. All in all a great upgrade for the Daysailer.
Harken Big Bullet Exit Block with #150 Cam Cleat
Description Pivoting exit/cam
Sheave dia. (in) 1-1/2
Length (in) 3-1/8
Weight (oz) 8
Max. line dia. (in) 3/8
SWL (lb) 300
Breaking strength (lb) 2000
Installs with 2 rivets or bolts.