(Click to see larger image) This tubing is quite flexible "Tygon-type" tubing with an inner diameter of 1/32 inch (0.8mm) and can slip over the end of 1 mm outside-diameter glass micro-capillary tube needles when they are used with V-groove type needes holders like the H-7. Alternatively, you can get round the tedious process of slipping tubing over thin glass by using a quick-change needle holder like our Tritech Research MINJ-4, Brass Straight-Arm Needle Holder. (Quantity 1 gets you a 1 meter piece, Quantity 2 gets you a 2 meter piece, etc.)