pure copper material, have been tested for hundreds of times in durability, still work copper nozzles could last even than aluminium nozzles. All copper nozzles have a built-in leakproof steel ball, no matter in pre-heating process, in use or after use, there be no leakage from the nozzle. Suitable for 98% -ns on the market, We suggest using high power -n for the long nozzle to achieve the perfect using effect. Simply replace the old nozzle with for the -ns that have never been used before. For the -ns that have been used before, plug in the power and start preheating for a few minutes, then remove the old nozzle using spanner(DO NOT USE YOUR HANDS IT'S VERY HOT) and replace it with Colour:As Shown Material:Metal Size:2.0x70mm Package Contents: 1x Nozzle Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.