This 2 piece glass lid set feature oven-safe properties to help ensure extended use during oven cooking, with silicone edges that fit effortlessly on the pans and provide an extra secure fit. The steam release vents create an outlet for high pressured steam to emit and an indentation gap for securing the handle attachment (sold separately). The dishwasher safe materials offer a low maintenance cleaning alternative, or simply perform a hand wash to maintain their superior graphite appearance.