Yongnuo 40mm Pancake f/2.8 - It's Cheap, but is it Worth a Damn?
Lens Review - yongnuo 40mm F2.8 | Flickr
With Usb Port For Nikon Camera Yongnuo 40mm F2.8 Lens Light-peso Standard Prime Af/mf Auto Messa A Fuoco Manuale Lente Yn40mm - Buy Lens For Nikon For Canon Camera Yongnuo 40 Mm