Pre-installation site survey: After the user purchases OVERTOP products (subject to the contract with the agent), OVERTOP will dispatch OVERTOP certified engineers to the user site to conduct pre-installation surveys according to user requirements. Provide specific requirements for the load-bearing and operating environment (temperature, humidity, dust, sunshine, corrosive gas, etc.) of the UPS system installation. It also issues a site survey report to assist users in arranging the preliminary work in place.