The Paslode HT-550 is a hammer tacker built for the swing-and-strike work that a squeeze stapler can't keep up with: house wrap, roofing felt, insulation backing, and carpet padding all go down fast when you can just swing the tool like a hammer and let it drive the staple on contact.It runs 20 gauge staples with a 1/2 inch crown, sized for 1/4 to 3/8 inch fastener lengths, and holds two strips in the magazine so you're not stopping to reload every few minutes. At 2.6 lbs it's light enough to swing repeatedly through a full day of wrapping a house or tacking down felt paper without wearing out your arm. The heavy duty build in a black and silver housing is meant for jobsite use, not occasional craft projects.Good fit for contractors, roofers, and remodelers who need to fasten lightweight sheet materials quickly and don't want the cost or hassle of a pneumatic gun for this kind of work. Model: HT-550 Gauge: 20 (1/2 inch crown) Fastener length range: 1/4 to 3/8 inch Magazine capacity: 2 strips Weight: 2.6 lbs Manual hammer-action, no cords or air hose needed