I have three Avery Dennison Swiftach gun, one is an older model and two are Mark III. I wanted needles that would work with V fasteners I own to attach labels to Oriental rugs. After my last older needle to the older swiftach broke, I couldn't use my V fasteners anymore. The MarkIII with heavy duty needles works, but I can't find V fasteners that work with it OR straight fasteners that have heads large enough for my tags, which are standard rug tags. The tags are constantly coming off the fasteners.