Short tube is 45mm long. Long tube is about 53 mm in length. Inside diameter of the large tube is approximately 2.1 mm. Inside diameter of the small tube is approximately 1.7 mm. The small tube is perfect for those Serin needles. I've been cutting the tubes down to about 1 inch by special order. If you need other custom length tubes, please mail me the plastic insertion tubes which come with your needles. I'll cut and polish silver tubes to the same length and similar inside diameter and mail them back to you.