Feature 1 Aviation aluminum main body, CNC precise machining, surface anodic oxidation treatment, wear and corrosion resistance, maximum size with knob about 227mm length, 53mm width, 27mm height. 2 Equipped with stainless steel gear screw zoom rod, stainless steel cluth, intermeshing spiral power transmission device. 3 Can moved back and forth over precise distance for fine focusing, convenient for macro photography, maximum horizontal load tested weighs around 7kg. 4 Standard swallowtail slot for quick mounting on any for Acre/RRS specification quick installing mount. 5 Professional manufacturing, fine workmanship, sturdy, durable and long service life.Condition: 100% Brand NewItem Type: Macro Rail SliderModel: MFR-150SMaterial: Aluminium AlloyFixture Type: KnobType Color: BlackWeight: Approx. 402gScrew Rod Adjusting Range: Approx. 110mm/4.33inchTotal Adjusting Range: Approx. 220mm/8.66inchScrew Each Circle Rail Slider Running Distance: Approx. 1.25mm/0.05inchScrew Rod Thread Distance: Approx. 1.25mm/0.05inch Package List1 x 150mm Macro Rail Slider1 x Internal Hex Wrench