1.Can I get a sample to check your quality? Yes,we are pleasure to provide sample for checking before bulk order. 2.What's your delivery time? 15-20 days,depends on your quantity. 3.Can we customize our own logo or color? Yes,we accept OEM/ODM. 4.What's the quality guarantee policy? We offer one year warranty for controller,battery and motor(without damaged by human behavior). 5.What is your terms or payment? T/T and L/C. 6.How do you control the quality? We have QC team comply with TQM and AQL,each step is in the compliances to the standards.As the same time,we will take photo and show vedio to you.