This is a set of three Pentax K-mount macro extension tubes. Pentax genuine, AUTO EXTENSION TUBE K SET This is a set of three K-mount macro extension tubes equipped with an aperture linkage lever. No. 1 Total length: approximately 9.5mm No. 2 Total length: approximately 19mm No. 3 Total length: approximately 28.5mm The case shows signs of aging on the surface, but the extension tubes themselves are clean. Thank you.