mount adapter is designed to allow for Canon EF mount series lens to be used on M4/3 camera. Plus 0.71 based on the focal length (equivalent focal length=focal length x0.71), which help enlarge 1 level aperture. Build-in 4groups, 4pcs optical glasses, AF(auto focus) and adjustable aperture, etc. Features: Gold-plated electronic contact, Auto-focus function. It can realize AF, adjustable aperture from camera body to lens's aperture. More durable metal material. Allow for Canon EF mount series lens to be used on M4/3 camera. Focus length multiplier: 0.71x. Compatible Micro Four Thirds Camera: Olympus E-M10/E-M10||/E-M10/E-M5||/E-M5/E-M1||/E-M1/E-PL8/E-PL7/E-PL5/E-PL3/E-PL2/E-PL1/PEN-FE-PM2/E-PM1/E-P5/E-P3/E-P1/E-M5; Panasonic GH5/GH4/GH3/GH2/GH1/GF9/GF8/GF7/GF6/GF5/GF4/GF3/GF2/GF1/GX85/GX8/GX7/GX1/G7/G6/G5/G3/G1/G1. Compatible lenses: Canon EF 11-24mm F7.0L USM Canon EF 16-35mm f/2.8L II Canon EF 17-40mm f/4 Canon EF 20-35mm f/2.8 L Canon EF 20-35mm f/3.5-4.5 USM Canon EF 24-70mm f/4L IS USM Canon EF 24-70mm f/2.8L II USM Canon EF 24-105mm f/4L IS Canon EF 24-85mm f/3.5-4.5 USM Canon EF 24-105mm f/3.5-4.5 Canon EF 28-80mm f/3.5-5.6 II Canon EF 28-135mm f/3.5-5.6 IS //E7 Canon EF 70-200mm f/2.8L IS II USM Canon EF 70-200mm f/4L Canon EF 70-300mm f/4-5.6 Canon EF 14mm f/2.8 L Canon EF 24mm f/2.8 Canon EF 24mm f/1.4L Canon EF 28mm f/1.8 Canon EF 35mm f/1.4L Canon EF 35mm f/2.0L Canon EF 40mm f/2.8 STM Canon EF 50mm f/1.8 II Canon EF 50mm f/1.4 USM Canon EF 50mm f/2.5 Canon EF 85mm f/1.8 USM Canon EF 85mm f/1.2L II USM Canon EF 100mm f/2.0 Canon EF 100mm f/2.8 Macro Canon EF 135mm f/2.0L Canon EF 180mm f/3.5 L Canon EF 200mm f/2.8L Canon EF 300mm f/4L IS Canon EF 400mm f/4.0 DO IS USM Canon EF 400mm f/5.6L Canon EF 500mm f/4L IS USM Tamron AF 17-50mm f/2.8 Di-II LD 18-270 F3.5-6.3 SP24-70mm f/2.8 Di- VC USD 150-600mm f/5-6.3 SP35MM F1.8 DI VC USD SIGMA 24-35mm f/2 DG 24-70mm f/2.8 DG 70-300mm f/4-5.6 DG 120-300mm f/2.8 DG 24mm f/1.4 DG 35mm f/1.4 DG 85mm f/1.4 DG YONGNUO EF 50mm f/1.8 Specifications: Model: EF-M2II Compatible Lens: For Canon EF mount series lenses Compatible Camera: For M4/3 series cameras Focus Mode: Auto focus Focus Length Multiplier: 0.71x Optical Glasses: 4 groups, 4 glasses Tripod Socket: Cu 1/4" * 1 Diameter and Length: ??67mm??25mm Front Cap: Camera cover Rear Cap: Lens dust cap Item Weight: Approx. 138g / 4.9oz (excluding cap) Package Size: 11 * 10 * 6cm / 4.3 * 3.9 * 2.4in Package Weight: 246g / 8.7oz Package List: 1 * EF-M2II Mount Adapter 1 * Front Cap 1 * Rear Cap 1 * User Manual (English & Chinese) Note: It is normal that it is a bit loose when the lens mount adapter is installed on Panasonic camera and a bit tight on Olympus camera. Camera and lens are not included.