Lens Collar Tripod Mount Ring for Sigma TS-31 APO 120-300mm f/2.8 EX, 120-400mm f/4.5-5.6, 150-500mm f/5-6.3, 50-500mm f/4.5-6.3 DG OS HSM; 80-400mm f/4.5-5.6 EX(DG)OS, 50-500mm f/4-6.3 EX DG(RF)/ HSM