On one of the early Gemini missions, a minor problem developed in the capsule while in orbit. In discussing possible solutions with engineers on the ground, one of the astronauts said, "I wish I had a roll of duct tape." He was joking... but the engineers looked at each other and said, "It's a good idea; make a note of it." Before the next flight, a team of NASA material scientists, space flight experts, and engineers studied the market and selected the best duct tape, 3M 3939. And it's been on every US manned space mission since. With each new mission, they make a new study, but have consistently come to the same conclusion: 3939.This, 3M 3939, is the duct tape that famously saved Apollo 13. This is the only duct tape that NASA reaches for when, "We've got a problem."And 3939 is the only duct tape that I reach for when I've got a problem. Yes, it is more expensive, but you use less and get better results because it is a superior product. It sticks well. It conforms well. It cuts and tears cleanly. And it doesn't deteriorate and get dry or gummy as other duct tapes do. It works well and gives good results. Once you have experienced a superior duct tape, once you have seen the results and seen how a superior duct tape can help you solve problems faster and better, you will not want the cheap stuff again.