This Heavy Duty Deck Hinge has a flat base and a 90 degree angle when mounted with 1/4" (2) fasteners. Although the fasteners and pin are not included, this hinge is designed for our #88BSC.1 large black knob with a 5/16”-18 (8mm) thread. Lastly, it has a 316 stainless steel mirror finish, being extremely durable for long-term use without corrosion. *fasteners and pin are not included.