SOMERSET, Wis. (KARE) — A student at a high school in Wisconsin has invented a device to keep intruders out of classrooms.Somerset senior Justin Rivard was inspired in his shop class to try to save lives at his school.He calls it the “JustinKase,” made of steel plates and connecting rods, Justin’s device slips beneath a classroom door and latches to the door’s jam.With his device in place, Justin has yet to find a person who can push a classroom door open, including linemen from his high school football team.“You can lock a door with a lock, it can get shot out,” Justin says. “You can lock a door with this, it can’t get shot out. You can’t get around it.”Somerset High School ordered 50 of them, one for every classroom in the building, then the middle school and elementary school followed.Justin has already delivered 54 of his devices to the Grantsburg School District, with 40 more on the way.