There are two tire plug kits I recommend above all others I’ve tried: The Extreme Outback Ultimate Puncture Repair Kit, and ARB’s Speedy Seal kit.

Each has its advantages. The ARB kit comes in a snap-in, well-organized blow-molded case, so everything you need is easy to access and nothing you don’t need is in the way. The reamer and plug insertion tool are stoutly made with solid aluminum handles—critical for working on tough all-terrain tires. (Never, ever buy plastic-handled plug tools.) Included are pliers for pulling out whatever has holed your tire, a razor for trimming the inserted plug, lube to ease insertion (no wise cracks please!), a tire gauge, and a kit containing spare valves and valve cores, valve caps, and a valve tool. Finally, 40 plugs are included, which should suffice for a very long time—except see below.

The Extreme Outback Ultimate Puncture Repair Kit is the one you want if you are heading out to drive around the world, or you are a professional leading self-drive tours, or if you just want to guarantee that you can repair any tire issue short of a carcass-shredding blowout. In addition to everything in the ARB kit (except the pliers), the EO kit includes an exhaustive selection of patches and rubber cement to repair seriously large punctures or even sidewall tears from the inside out, once you have broken the bead and removed one side of the tire from the rim. There are even thread and needles to sew up sidewall tears before patching them, and such thoughtful additions as a piece of chalk to mark where your tire and rim meet, so when you remount the tire your balance will not be lost, and packets of hand wipes. The one downside not shared by the ARB kit is that all this stuff is crammed into a heavy-duty zippered nylon case. It’s amazingly compact, but you need to pull just about everything out to accomplish even the simplest plug job.

Also included are plenty of plugs—but, as with the ARB, there is a problem.

I’ve always maintained that the plugs in the ARB kit, which are about 8mm in diameter, are far too large for the average nail or screw hole. They are extremely difficult to insert in such a hole in any tire with a tough carcass, especially a stout E-rated AT, even after a vigorous reaming.

Up until recently, the Extreme Outback kit included two sizes of plugs, about 6mm and 4mm. The 4mm plugs were perfect for most small holes—in fact, when teaching tire repair and actually drilling 3/16th-inch holes in tires for students to practice on, the thin plugs were all I used. Only when demonstrating more challenging situations did I need the larger sizes.

Now, however, the EO kit only comes with 6mm plugs, which, while easier to insert than the ARB’s, are still problematic for many repairs. Case in point: At the last Expo I was having students plug tires after I drilled holes in them. The first volunteer was a woman, and she simply could not get a plug from the EO kit inserted, even with plenty of lube and while putting virtually all her body weight on it. Finally Mark Kellgren, who was teaching with me, took over—and had nearly as hard a time getting the thing in there. Finally I realized I had unwittingly run out of the 4mm plugs and had substituted one of the thicker ones, which was clearly too large for such a hole.

I called George Carousos, who owns Extreme Outback, and he told me the kits were no longer available with the thinner plugs. So I decided it was time to hack all our ARB and EO kits. I looked up Safety Seal, a company that has been making tire repair products for half a century, and ordered a box of their slim plugs. At a listed 3.2mm these should be smaller than the old thin EO plugs, but if anything they look a tiny bit thicker. Nevertheless they should suffice for those smaller holes. So I’ve replaced half the thicker plugs in all our kits with thinner versions, which should make each kit far more versatile.