Sentry is made from segments of Schedule 40 black steel pipe. Its segments are cut with 17-degree angles on both ends. On their wider side, these segments are connected with steel rods that have been fashioned into hinges. Its dark, heavy exterior makes it seem militaristic. A metal circle at one of its ends, frames a glass lens. Is it watching? Is it protecting or surveilling? Although it lives, hanging on its steel shelf, it can be taken off and closed up, forming nearly a protective full circle.