<p>This cap is made of strong ABS plastic to protect mount and rear glass of your lens. It fits Arri PL (Positive Lock) lens mount.</p> <p>The cap holds firmly on the lens mount due to catching lugs - it will not fall off accidentally. Just put it onto lens mount and turn it clockwise to lock it.</p> <p>Manufacturer and the cap type are indicated on the inner bottom of the cap.</p> <p>Weight is 17 g.</p> <p>Improvements are:</p> <ol> <li>Wedge-shaped locks. This feature guarantees reliable hold of the cap on the lens mount.</li> <li>2x45& dergees chamfer on the inner edge. This feature provides 100% compatibility with any PL lenses since some of them have 45 degrees chamfer at this junction.</li> </ol>