Gadget Place 1 Dimension Focusing Rail for Olympus OM-D E-M5 II E-M10 E-M1 It is made of metal with black anodized finishing. It is ideal for taking closeup photos and other photos require fine-tuning adjustment in focusing. There are scales marked on the rail for high precision reference. The position of rail can be tightened after adjustment is achieved. There is standard tripod thread 1/4" on the bottom allows mounting it on almost any tripod / tripod head.