Buy from Amazon.com : http://fave.co/1MGsDYG <br /><br />Sigma EF-530 DG Super Electronic Flash for Nikon DSLR<br /><br />Product Description : <br />Powerful Guide Number of 174 ft 53m at 105mm Setting <br />Designed to work with the new TTL systems of all the popular manufacturers <br />Fully compatible with all Nikon Digital SLR cameras including the D40 and D40X <br />Covers a focal length from 24mm to 105mm <br />Autozoom function automatically sets the optimum illumination angle
