The 1890U Pneumatic 18-Gauge 1/4-Inch Narrow Crown Underlayment Stapler is a Heavy-Duty, narrow-crown stapler specifically designed for fastening underlayment. Its high capacity magazine can be loaded with up to 260 staples for applications requiring heavy fastening. This allows the user to work longer without having to reload, improving efficiencies and helping you make deadlines. The Model 1890U accepts 18-Gauge, Narrow-Crown (1/4) staples in lengths from 1/2 in. to 1-1/2 in. Its non-marring nose helps to protect work pieces while allowing you to drive staples at the perfect depth. Offering both sequential and bump-fire operation, this tool decreases operator fatigue and increases productivity.