Pic Rail Brass Catcher with Heat Resistant Mesh and Zippered Bottom Zipper Design.Padded mesh with zipper closure can be used to effectively emptying and safely transport brass casings.Convenient Use.Quick detent locking and separating, easy to install and change.Practicality. Mounts anywhere on picatinny rail compatible with most models.Bearing Weight.Ideal for reloaders and easily holds 100 rounds of empty brass.If you have any questions or difficulties, please contact us, we'll be glad to help you. GLORYFIRE Pic Rail Brass Catcher with Heat Resistant Mesh and Zippered Bottom for Picatinny Mountable Quick Unload.