The Chauvet Pro OHDLENS36 Ovation Ellipsoidal 36° HD Lens Tube Black is a fixed focal length lens tube for Ovation E-Series fixtures and other standard ERS-style fixtures. It uses high definition glass optics and dual aspheric lenses to provide precise focus for crisp gobo projection. The lens tube has a 36° angle for controlling output and includes an integrated gel frame holder with a gel frame. Its rugged housing is designed for touring, broadcast and theatrical production.