OD=3mm, ID=1.8mm, L=1/4 1/2 1 1.5 inch, density 18g/cc Normally this tube used without coating, but if you want coating or painting, we can supply.Brass tube, copper tube, alluminum tube also available. the picture is only example, what we can do is much more than picture showing, some customer do not allow us to put picture here.