Description: 1. This adapter can helps you mount your M42 lens on Camera with EMF AF Confirm. 2. Allows focusing to . 3. Supports AV (Aperture Priority) and Manual Mode. 4. The chip enables camera viewfinder focus confirmation light and confirmation sound. 5. EXIF is fixed F1.1 to F64 / 1mm to 65535mm . Method for setting program: 1. Setting the maximum aperture on lens. 2. Setting the desired aperture on camera. 3. Focus and meter the object, when focus is achieved. 4. Setting the lens aperture to the same desired aperture as the camera setting. 5. the shutter button and take the picture. The ring has 3 setting modes: Mode 0- enter your lens'maximum aperture. Mode 1- enter your lens' length. Mode 2- enter your lens'focus Mini adjustment. Turning the aperture dial to specific aperture value and shutter button to enter a desired setting mode. For example, if you want to enter the lens' maximum aperture, turn the aperture dial to F/2.0[which means Number 0 to the ring] and shutter button. You are setting the ring in maximum aperture enter mode. : 1. Don't touch the golden contact points of the circuit board of emf chip when attaching and detaching the ring to your lens and camera. 2. Don't use F/64-shutter + F/57- shutter + F/64 - shutter combination in normal shootings. This combination set emf chip to setting up mode. If you unintentionally enter this mode, choose a aperture value between F/6.3 and F/51 and shutter button once to exit. Compatible with: All M42Lens for 5D Mark III, 5D Mark II, 5D, 7D, 70D, 60D, 50D, 40D, 30D, 100D, 700D, 650D, 600D, 550D, 500D, 450D, 400D, 350D, 300D, 1100D, 1000D. Not work with for 30, 30V & 33V and 1D series. Material: Metal colour: Black Package Contents: 1 x Lens mount adapter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.