The ALZO 16 inches clip-on aluminum barndoors are useful for adjusting light intensity through a diffuser and for masking off light and controlling background wash. They include a 2 point clip mount with thumbscrew fasteners and they can be oriented in a wide variety of positions, making them very adaptable. Their 16 inches height and 9 inch length is a very effective mask. Ideal for use with round and square reflector lights with up to a 1/4 inch thick lip. They are sold as a kit of 2 and total weight is 1.5 pounds.