Taking a chance on Alibaba for my solar panel setup, I wasn't sure what to expect. But let me tell you, Penny Pan at Shenzhen First Tech was a game-changer! Unlike other sellers who just push products, Penny took the time to understand my entire system (panels, inverter, string setup) before recommending the perfect PV optimizers. The optimizers themselves are fantastic - well-made and surprisingly easy to install, even for a DIYer like me. The only hitch? They don't track individual panel performance. But for the price, that's a minor quibble. Speaking of fantastic, Shenzhen First Tech's customer service is top-notch. When I had an issue with 3 optimizers, they were incredibly helpful and replaced them without any fuss. Overall, this Alibaba adventure turned into a stellar experience thanks to Penny Pan's expertise and Shenzhen First Tech's smooth service. Highly recommend!

First time buying on Alibaba and I was a bit worried, but Penny Pan from the Shenzhen First Tech Co., Ltd. was amazing! She asked me all about my solar system (panels, inverter, number of strings) before recommending the perfect PV optimizers. The optimizers themselves are great: well-made and easy to install. The only downside is they don't track how each solar panel is doing (PV level monitoring). But considering the price, they're still a good deal. Their customer service is also excellent! I had a problem with 3 optimizers, and they agreed to replace them without any hassle. Overall, a fantastic experience!