The 100W Xantrex Solar panel features mono PERC 5 Busbar cell technology to improve module reliability and efficiency UL Certified to ensure the highest level of safety performance and quality for a flexible solar module Extreme Vibration Tested to ensure mounting stability and safety in the rockiest driving conditions Check out the Xantrex YouTube channel for a video of the test UL 1703 Certified to the solar industrys recognized standard for solar module safety