TeacherGeek plastic angle brackets are a clever solution for constructing three-dimensional STEM | STEAM projects, including frames, bridges and more. Durable and flexible, they can join components at various angles (15˚, 30˚, 45˚, 60˚ or 90˚) again and again. Splined corner holes fit dowels securely or can be reamed for rotation. An excellent choice for Rube Goldberg machines, crazy contraptions or projectile launcher activities. Reusable, kids can tinker forever!