1.The indicated price is for 18 meters of this product. Diameter: about 4mm Note: There might be chromatic aberration due to different shooting light, angle of shooting, display resolution in different PC and so on, thanks a lot for your understanding and we will do our best to serve you. You can mix colors when place the an order. Please tell me how many pieces do you want for each color, I will check the stock to see if they are enough for your demands. 2.Customers service : If you have any doubts or questions, please tell your doubts in time. I will do our upmost to explain and show the facts(details) and give you a satisfying answer. If you are satisfied with your purchase, please leave a positive feedback and high scores rating. After receiving the feedback,I will do the same for you. Both of us benefit from the positive feedback.