This heavy duty staple gun is the ideal manual crown stapler for your upholstery, fencing, framing, or other job. The 3-in-1 hand nail gun works with D-shape, U-shape and T-shape staples. It's a great tool to have around your home or workshop. The manual staple gun doesn't need any electrical power, it just uses the power of your hand, which means you can use it anywhere you go. It has easy to learn mechanism. You just take out the spring-loaded staple slot, insert the nail strip, and put the staple slot back in. In case of jammed staples, the bottom can be removed in order to get the jammed staples out. The heavy duty tacker has a knob on the top, which is used to adjust the depth of nail penetration.