Adapter is sturdy, made of metal. It locks on properly and does not wobble. It allows focus to infinity. It has glass elements. Adapter will allow to use Nikon G mount (without aperture ring) AF-G lenses on Sony E mount cameras ( such as ?5100 ?6000 ?6100 ?6300 ?6500 ). Adapter does not have any electronic contacts, so it will not communicate with the camera. You will have to adjust aperture and focus manually. All items come with 90 day money back guaranty. Shipping is free within USA and $10 via USPS first class mail service worldwide. You can choose faster and more expensive shipping during check out. Booster coverts full frame lenses into APS-C lenses. The advantage is to get the full fame field of view onto the APS-C sensor. Specs: Max. f-stop pass through: 1.4 Optical design (lenses / groups): 4/3 Focal length extension: 0.7x Image diameter (mm): 28.5 Bayonet front: 135 full frame lens Bayonet back: E mount