The mbs 100 15mm type m matte box support from vocas is a 15mm lightweight rail support designed for use with the canon eos c300 camera to provide protection for the camera and lens its compatible with other 15mm accessories such as lens supports and follow focus this type m matte box support comes standard with a set of 15mm rails that are 350mm in length its also directly compatible with the arri bp 8 19mm rail support