Merge pull request #1052 from arduino/kateryna-lukina-patch-3-1

Update product.md

Author: kateryna-lukina

content/hardware/07.opta/opta-family/opta/product.md

@@ -3,7 +3,7 @@ title: Opta
 url_shop: https://store.arduino.cc/collections/pro-family
 url_guide: /tutorials/opta/getting-started
 core: arduino:mbed_opta
-certifications: [CE]
+certifications: [CE, UL]
 ---
 
 The **Arduino Opta®** is a secure, easy-to-use **micro PLC** with Industrial IoT capabilities. Designed in partnership with **Finder®**, a leading industrial and building automation device manufacturer.