Sigma TS-21 Tripod Collar for Select Sigma Telephoto Lenses Sigma TS-21 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) Available for: APO 135-400mm F4.5-5.6 DGAPO 170-500mm F5-6.3 DGAPO 70-200mm F2.8 EX DG MACRO HSMAPO 70-200mm F2.8 EX DG /HSMAPO 100-300mm F4 EX DG /HSMAPO 120-300mm F2.8 EX DG HSMAPO MACRO 150mm F2.8 EX DG HSMAPO MACRO 180mm F3.5 EX DG /HSMAPO 300mm F2.8 EX DG /HSM Mount: 1/4"-20