The plate is a perfect fit, positioned snugly below the existing Gitzo plate, inside the "basin." Once installed, the Gitzo plate can not move or loosen, therefore preventing the head & photo equipment from falling. The plate is also available in another size to fit the newest Gitzo 35 series Carbon fiber tripods as well as some older tripods.
The GSP-55 is for use with the GT5541LS and the older GT1548.