A Corner Applicator Box is used to apply a steady flow of joint compound over taped inside and outside corners. PREMIUM MATERIALS | Made of high quality, anodized aluminum and a long-wearing urethane wiper seal. HIGH-QUALITY CONSTRUCTION | Lab-tested to more than 100,000 cycles with no visible wear or leakage. MADE TO LAST | Our tools are built for reliable, daily use on the job site. GUARANTEED PERFORMANCE | Made to exceed your expectations, and backed by an industry-leading 7-year warranty. PROFESSIONAL GRADE | LEVEL5 drywall automatic taping and finishing tools have been designed and built using nearly 20 years of input from professional finishers. Features Heavy-gauge aluminum housing Precision-machined components Premium urethane wiper gasket - lab-tested to more than 100,000 cycles with no visible sign of wear or leakage Large, sturdy handle bracket prevents any pressure plate warping during use Full stainless steel cone for long service life 7-year, no-hassle warranty