This is SMJ 33x16.7x1mm Thin Type Tungsten Weight Plate 11g. A thin tungsten plate with a thickness of 1 mm. Just fits the slit of the carbon chassis of INFINITY IF 14-2. Of course, it can be used by pasting it on other parts of the chassis.
SMJ 33x16.7x1mm Thin Type Tungsten Weight Plate 11g (1 pc)