More commonly called "midship cleats" .... I got mine from Garhaurer. Well worth the $50 I paid a few years back. Standard T Track, 1 or 1.25 inch. . You need to know if you have standard T track... if it's another kind it may be proprietary, such as Harken's. But, Shaeffer, Lewmar, Ronstan, Garhaurer etc all use the standard T track.What brand and type of adjustable spring cleats are are people using on C315 Genoa tracks?
We have the Shaeffer cleat pictured above and it is very high quality. I like that you can put the dockline loop through the middle of the cleat which you cannot do with the other version. After a few years of moving one cleat from side to side we finally bought a second for our 310.Many years ago, when I began promoting midship springline cleats on tracks for those of us who didn't have them installed as OEM on the side decks, one skipper wrote in to say thanks for the idea.
Then he went on to describe how he was able to move it from one side of his boat to the other depending on where he docked when cruising.
I suggest you buy two , one for each side.