You have a GGTS see-number 834. That number could be an Alu-tube from 2010 with engraving To my friend, or a SS-tube form 2011 without To my friend. It seems to be the 2011 edition, and there were made about 1400 of them. Yours look real nice with very good engraving. Take good care of it, and congrat with a beautiful GGTS