Service： I explored sourcing electroinc parts for my PCB project on Alibaba and in doing so conversed with a number of Alibaba representatives.  However, once I came in contact with Serena there was no need to explore any further!  Serena has far exceeded my expectations wrt to customer service and support!  She has answered all of my inquiries accurately and promptly and the time difference between our individual countries has not been a henderance at all, and she has been available seemingly early mornings into late evenings as well as weekends!  Her quotes have been very competitive and she has explored alternatvies and options where I needed to consider adjustments to my PCB design.   She has also identified to me some of the other services her company provides and has provided supporting links and documentation.  In summary, I have absolutely no hesitation in giving Serena 5 out of 5 stars for her supior service and support!  Thank you Serena!! Delivery： see above.