Paracord

Paracord was originally used in the suspension lines for parachutes. The kind used by the US military for this purpose is Type III, or #550 paracord. It is made of nylon, and consists of an outer jacket with seven braided inner threads. Only about 3/16 of an inch thick, it can support up to 550 lbs (under perfect test conditions). Paracord generally has very good strength for is thickness compared to other common kinds of rope, and because of its tough nylon construction, it is resistant to rot and abrasion.

There are various types of paracord, Type I, Type II, Type III and Type IV, with increasing roman numerals indicating increasing cord strength and and an increasing number of inner braids which can be separated out of the main cord to be used in emergency situations as fishing line or sewing thread.