HighPro introduces the Model AS-4090 pneumatic, tongue-and-groove stapler, designed to staple down 5/16- to 5/8-inch thick engineered and solid flooring. The AS-4090 drives 1-, 1 1/4-, and 1 1/2-inch, 18 gauge quarter-inch narrow crown staples. The stapler is designed with a unique trigger and safety combination, according to the company.