Opteka Auto Focus DG EX Macro Extension Tube Set for Canon EOS Digital SLR Cameras (12mm/20mm/36mm Tubes)
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 Canon EOS SLRs * Contains three tubes of different length, a 12mm, 20mm, and 36mm * Glass-free; Lightweight * 1 Year Opteka Warranty