John Lewis is installing the labels in their Exeter store as a pilot test of NetTickIT, the integrated digital label management system developed by Pierhouse. These labels are designed to be updated wirelessly, removing the need to go around and change the labels one at a time. They have installed several hundred labels in the electronics dept.
ZBD Solutions makes the shelf labels in a number of sizes ranging from 2.5" to 5", with the smallest intended to go on the edge of a shelf and the larger sizes designed to be used on display tables like you see above. John Lewis looks to be using one of the intermediate sizes.