Opteka Auto Focus DG EX Macro Extension Tube Set for Nikon 1 J5, J4, J3, J2, S2, S1, V3, V2, V1 and AW1 Compact Mirrorless Digital Cameras (10mm/16mm/21mm) Extension tubes are designed to enable a lens to focus closer than its normal set minimum focusing distance. Designed with all the circuitry and mechanical coupling to maintain auto focus and TTL auto exposure with Nikon "1" series cameras and lenses Contains three tubes of different length, a 10mm, 16mm, and 21mm Glass-free; Lightweight 1 Year Opteka Warranty