Fotodiox Pro Automatic Macro Extension Tube Kit for Micro Four Thirds (MFT) Mirrorless Camera System Kit of two extension tube sections: 10mm and 16mm - Any combination of tubes can be used for various reproduction ratios Designed with all the electrical and mechanical couplings to maintain auto focus and TTL auto exposure Extension tubes are designed to enable a lens to focus closer than its normal set minimum focusing distance No optical insert - maintains lens optical quality while remaining lightweight 24 month manufacturer warranty