Hilco offers a broad range of measuring devices: metal and plastic PD rules, lens thickness calipers, and seg-height measuring gauges to name a few! Try our new PD meter for the latest in measurement technology. Hilco Rx Trays are available in 2 configurations: Standard and deep. Seven different colors are available in both styles. Try our Rx Tray Modular Housings, a unique snap together system to conveniently store repair parts.