Harken's low-friction Micro Cheek Block is compact and lightweight, with fast trim and release under high or low loads. Ideal for sailboards, smaller dinghies, and for lightly loaded control lines on boats of all sizes. Great for anchor trolleys.
I used these blocks on my fourth anchor trolley (both ends as JWil indicated earlier). These blocks are slick, and the perfect size for your anchor trolley. Easy to install with pop rivets as there is plenty of room in the design for the gun tip. They will become my standard order for each kayak in my future.
Works like a charm, really smooth. I use it on a trolly anchor system, both ends.