This moved the main sheet cleat forward and up where it is easy to get hold of and also easy to move behind when tacking. I used to have a problem with water coming up through the centerboard slot. After a little silicone sealant was added around the lower edges here, all that stopped. You can barely see two of the 4 holes I filled where the old fitting for the main sheet cleat used to be on the floor. The whole arrangement comes apart easily with the help of an electric screwdriver. I have since replaced that main sheet cleat with a ratcheting main sheet cleat similar to this (picture from another boat).