Duct tape

Just pondering what the most important bits and pieces are for expeditions to remote areas. Especially in vehicle-based expeditions we travel with a (too?) large selection of electronic devices and comfort-enhancing gear but it is often the very simple stuff that is most important and saves the day. Here is part one of my selection:

Duct tape (also know as duck tape): it's usefulness no longer needs to be proven. On Apollo 13 it saved the astronaut's lives after an explosion had damaged the CO2 scrubbers  and a few years later on the moon during the Apollo 17 mission it was used to repair the moon buggy's fender ( a must see at the National Air and Space Museum in Washington). More recently on Mars large quantities of grey duct tape were used to seal The Hab.  Best in my opinion is the standard silvery gray tape. Note that this tape cannot be removed without trace. If removal is important, use gaffer tape which is designed to be cleanly removed.
Chris