Sigma TS-81 Tripod Collar 150-600mm f/5-6.3 DG HSM OS Sports Lens Sigma TS-81 Tripod Collar - Sigma 1 Year North and South America Limited Warranty (3 Year USA Extended Warranty for a Total of 4 Years from Date of Purchase) Compatibility: Sigma 150-600mm f/5-6.3 DG OS HSM Sport Lens Thread Size: One 1/4"-20, femaleOne 3/8"-16, female