From the Manufacturer
FASCO F1B 50-16 Stapler Auto L/M: An adjustable automatic speed firing capability and a long magazine. Uses easy-to-find DuoFast 50 staples. Adjustment knob lets you pick the desired speed - from single shot to wicked fast. The double length magazine cuts loading frequency in half. Great for felt paper, house wrap, and any craft projects or screening job you'll tackle.