The set is consist of three tubes of different length, which can be used in any combination or individually to obtain the different magnification.This Extension Tube set provides 3 extension tubes that can be added between the camera and the lens, to make the lens focus at closer distances and produce higher magnification. Extension tubes are metal tubes with a rear-lens mount at one end and a camera-body mount at the other end.This Extension tube set does not affect image quality as there is no optics inside. In comparison, a close up filters are often blamed for degrading image quality. It moves the lens farther from the film or digital sensor.There are no electrical contacts in the extension tubes. Exposure and focus have to be adjusted manually. Aperture control is not available if you use a lens which does not allow you to manually adjust the aperture (Without an aperture ring).Note: There are no electrical contacts in the extension tubes. Exposure and Focus has to be adjusted manually. Aperture control is not available if you use a lens which does not allow you to manually adjust the aperture (without an aperture ring). Suitable for: Sony DSLR and Film SLR and Lens.Package: Macro Extension Tube x1Specifications:Dimensions: 2.80 x 2.60 inch / 7.1 x 6.6 cm (H x Diameter)Weight: 4.44 oz / 126 gMaterial: metal (not plastic)Color: blackKit includes: Camera Mount Coupling Adapter, Lens Mount Coupling Adapter, Extension Tube 1, Tube 2, Tube 3Compatible Cameras (including, but not limited to): Sony AlphaA-Mount Cameras DSLR a3500, A350, A900, A800, A230, A330, A380, A550, A500, A850,A450, A290, A390, A560, A580, A33, A55, A35, A65, A77, A57, A37, A99, A58,a3000, A77II, Minolta Maxxum 650SI, 800 SI, 5D, 7D, 7, 9xi, 7xi, 5xiThe more tubes you add, the closer the focus and the greater the magnification.There are no electrical contacts in the extension tubes. Exposure has to be adjusted manually. Aperture control is not available if you use a lens which does not allow you to manually adjust the aperture (without an aperture ring).Package Includes:1 x Macro Extension Tube Set(3 extension tubes)How to use:Please note: when tubes attached, you need to do all manually, and it is important that you use lot of light.There are some main steps how to use tubes:1) set your lens to maximum aperture (recommend);2) set-up camera and lens to manual mode, switch off and detach the lens;3) attach extension tube between the camera and lens (look for red dots and align on mount collars; attach same way as lens);4) put your camera on tripod, or better on rail system;5) put object close to the lens and use lot of light (2-3 flashguns, or 3x 500w lamps, or at least 1 strobe-light, or take pictures outside in bright sun);6) increase ISO, decrease shutter speed;7) focus by moving camera further or closer (if on rail system), or use manual focus ring on lens mm by mm (very slow) until object in focus. Please remember that DOF (depth of field) is very small.You don't need to use all tubes together - you can combine tubes - shorter length you use, in viewfinder becomes lighter, but again not as high magnification as with all tubes together.