Designed to seal up-slope profile ends. Popular applications such as: HVAC curb penetration, skylight curb penetrations and chimney flashing points. The Mastercap measures 3” high x inner depth of 2” and base width of 4 ½” will accommodate many standing seam metal roofing profiles from 1 ¼” to 3” and popular commercial roofing panels with an 1 ¼” to 2” tall rib such as MR12 / R Panel / PBR Panel. (20 units per box)