Features: and high quality. Application: Mini-rail for installation of trapezoidal photovoltaic panels on walkable trapezoidal metal sheet roofs with metal sheet . Good static load distribution. This type of installation reduces the suction effect of the weight of the PV system on the outer skin of the roof covering. No need to transport long profile strips, adjusted to the post spacing of the profile panels. Profile sections are pre-drilled and covered with sealing tape. Rail size: 200mm Middle clip: for solar panel 30mm Assembling: 1. The division of the roof depends on the size of the module. 2. Align the with chalk lines. 3. Place the bracket in place, pre-drill holes with 5.00 mm sheet metal and secure with 4 blind rivets. Or use a thin sheet metal screw to fix it without pre-drilling. 4. Place the row with a wooden template and after 10 rows, check the orientation again with a piece of string. note: The production batches are different and the colors of the accessories are random, Cannot be chosen the specific color.which does not affect the use. size: Material: Aluminum alloy colour: silver Package Contents: 2 x Rails(with accessories Gasket+Screw) 2 x middle clamp 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.