A single pre-wound type A bobbin of bonded nylon thread. Size is TH69. It won't run in most sewing machines but by far, this thread is the thread to use for patching gear. Each stitch you make with it has approximately 9.5 lbs of tensile strength. Multiply that by the number you need and add an additional 10%. Suitable for Size 18-24 needles which are available in hand needles for patch jobs. One bobbin should make several dozen bartacks. This same thread is used in the Adventure Medical Survival Kits and can be really handy while hiking, backpacking or just about any other adventure scenario.