Screw size: 6mm (M6). Standard Location Size: Width 3/4 “(19mm), Thick 3/8″ (9.5mm). Fit for 30mm/45mm T-track. Up to 87CM in length. Please pay for all items within 5 days after. Sometimes may delay one more week, as for your country’s customhouse. If you find any quality problems when you receive. We will resolve it in 24 hours. I’m sure everything could be solved by communication. Your total satisfaction is always our goal. If you have any question, please feel free to. Thanks for your cooperation.