Usage Tips:1. Main body made of Aviation Aluminum, CNC precisely machined, surface anodized, the maximum size with knob is about 170mm long, net weight is about 380g 2. With stainless steel gear spiral zoom lever, stainless steel clutch, intermeshing helical power mission, can move back and forth in precise mm distance for micro-adjustment focusing, convenient for close-up photography of micro-object, the tested maximum horizontal load weight is about 4kg 3. Compatible with for Arca Swiss/for RRS/for KIRK/for WIMBERLEY/for MARKINS/for SUNWAYFOTO/for KANGRINPOCHE/for BENRO/for SIRUI/for MARSACE quick release plate and ballhead of Arca Swiss/RRS standard fit; suitable for IS-JZ30/IS-JZ50/IS-JZ64/IS-QJ58/IS-QJ64/IS-JZ60BK/IS-JZ70BK/IS-JZ80BK. Net weight:about 380g Slide length:about 170mm Regulating range:about 125mm Lap length:about 1mm Maximum load:about 4kg Colour:Black Material:Metal Size:Outline size:about 200mm long, 50mm wide, and 35mm high (including knob) Package Contents: 1 * Macro Focusing Rail Slider Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.