What size is Smartscan Hydra head & face plate? Egli November 04, 2019 22:08 Updated Dimensions for the Smartscan Hydra face plate: 129 x 124 mm Dimensions for the Smartscan Hydra head: 96 x 86 mm Related articles How much does Automist cost? Where has Automist been installed? How do establish fitness of materials in the approved document published to support regulation 7? What is the installation process like? Will it cause disruption? Will it turn off if my electric meter stops? What if I have a prepay meter? Comments 0 comments Please sign in to leave a comment.