Walz Waltz Bayonet Type Square Metal Lens Hood for Twin Lens Reflex Cameras Measured with a ruler, the inner diameter on the lens side is approximately 42mm. I have included as many photos as possible so you can see the condition. Please purchase only if you can assess the condition from the images, are satisfied with the current condition, and understand that this is a used item stored at home. Please refrain from purchasing if you are concerned about minor scratches, marks, or wiping traces. Thank you.