Generic Autofocus AF Confirm Macro Extension Tube Plastic for Nikon 1 Mount Lens S1 J3 V2 J2 V1 J1 AW1 Extension tubes are designed to enable a lens to focus closer than its normal set minimum focusing distance. It comes as a set of 2 tubes of different lengths which singly or in combination on makes it usable in 3 different lengths, 10mm, 16mm, 29mm. Material: ABS(Acrylonitrile Butadiene Styrene), color : black