Nimar Extension Ring with Mechanical Zoom Control & Lock for Sigma 10-20mm f/3.5 EX DC HSM

This Nimar Extension Ring with Mechanical Zoom Control & Lock is compatible with the Sigma 10-20mm f/3.5 EX DC HSM lens and fits on underwater camera housings compatible with Nimar NIM-108 or NIM-108WS port systems. Depth-rated for 197', it is made of acetal resin and comes with two O-rings. For full compatibility info, see the NIM-108 (standard) Port Chart or the NIM-108WS (water sports) Port Chart.