Have a quantity of 10 75/3500 tubes for sale. Tubes have 3 grooves total. 2 internal and 1 external. These are 6061 T6 drawn tubing and cut and grooved to Gorilla specs. These tubes are not anodized. Please email Gary at gar741a@hotmail.com if interested. Paypal and shipping not included. Included zip to calculate shipping charge. Paypal and shipping charged are no additional funds for me. What they charge is what you pay. thanks Gary