Each tube can hold 4 or more knitting needles (for US 10.5 or smaller needles) or a smaller number of larger needles.
Tubes can hold needles up to 10 inches in length. Simply insert your needles into the Yellow tube and then slide the Blue tube over them. Push the Blue tube onto the Yellow tube as far as it will go. Your needles will then be protected! 4 tubes per package.