The led advertising company KEYTECHLED offers IoT and smart city application solutions to our customers. We work hard to offer the best smart city and IoT application solutions with the spirit of "concentration & innovation" as a leading global provider of smart city LED displays and IoT application solutions.Our company will conduct manual inspection according to the strict quality control list to ensure that it meets our high standards of VERV. All led advertising screens for sale must pass the 72-hour aging test before delivery.