EUROLITE barndoors are separately sold light-control accessories for STL/THA spotlights, designed to adjust the desired light beam. The accessory has a black, matte aluminium construction with a material thickness of 1.5 mm. It includes a mounting ring with an inside diameter of 150 mm and eight 5 mm mounting holes. M4 × 6 mm screws are used, and the spotlight slot measures 23.5 × 23.5 cm.