Canon Tripod Mount Ring "A"(B) for 200/2.8 L II

This tripod mounting ring works ONLY with the EF 200mm f/2.8L "II" lens.  Because of the lens' weight and length, it is necessary to employ a tripod mounting ring when working with the EF 200mm f/2.8L "II" from a tripod or monopod.  This achieves proper balance, and because the camera/lens combination can be rotated within the collar it also makes for simple switching between horizontal and vertical compositions.