Common size:1-16mm(+-0.02mm) Material:soda lime round glass balls Item, performance/ingredient, value 1, sio2, 72% 2, na2o, 15% 3, cao, 9% 4, specific gravity, 2.6-2.8g/cm3 Faq: Q1. Can i have a sample order ? A: yes, we welcome sample order to test and check quality. Mixed samples are acceptable. Q2. What about the production time? A:sample needs 3-5 days, mass production time needs 2-3 weeks for order quantity more than Q3. How do you ship the goods and how long does it take to arrive? A: we usually ship by dhl, ups, fedex or tnt. It usually takes 3-5 days to arrive. Airline and sea shipping also optional. Q4. How to proceed an order ? Firstly let us know your requirements or application. Secondly we quote according to your requirements or our suggestions. Thirdly customer confirms the samples and places deposit for formal order. Fourthly we arrange the production.