The MTB Plate with Transponder compares to the Chip Race Number, but it is made from a 300g/m² PVC substrate and thus is much thicker and harder. It is made to be attached to the handlebars using cable straps.
Note that the transponders do not need spacers since they are not attached to the human body. In consequence, the simple transponder on the MTB plate is much thinner than the bib transponder.