If you buy the Sigma F 105mm f/2.8 EX DG Macro OS HSM Nikon, you'll receive 1 year extra warranty from Sigma for free. You have until 8 weeks after the purchase date to register your promotional product for Sigma's promotion. Have a look at the promotional Terms and Conditions (PDF) for more information.
Type of photography
Macro, Nature and animals, Portrait, Product, Recording