Sigma Lens Hood for 17-50mm F2.8 EX DC OS HSM Lens Sigma Lens Hood (LH-825-03) - Sigma 1 Year North and South America Limited Warranty (3 Year USA Extended Warranty for a Total of 4 Years from Date of Purchase) Sigma Lens Hood for 17-50mm f/2.8 EX DC OS HSM Lens, 24mm F1.8 EX DG ASP Macro Lens and 28mm f1.8 EX DG Lens.