استخدام مرة واحدة Viltrox Automatic Extension Tube Overview Shortening the minimum focusing distance of Canon EF-mount lenses, this Automatic Extension Tube Set from Viltrox also enables you to achieve a greater maximum magnification for close-up shooting with any lens. This kit contains 12mm, 20mm, and 36mm tubes, which can be used independently or in combination for up to seven different lengths to suit different subject types. Additionally, integrated gold-plated contacts maintain full autofocus and auto-exposure functionality and feature durable aluminum-alloy mounts.