Grip H Clip is made out of nylon 66. It is installed and holds the roof sheathing half way between the trusses. The Grip H Clip is designed to be pre-installed and will grip the roof sheathing. It will stay in place while the roof sheathing is being nailed. Grip H Clip has lead-ins that allow the installer to easily install the adjoining sheet without the need to touch or adjust the clip. This makes installing roof sheathing faster, easier, and safer, especially on windy days. 1 bag each. Packaged in bags of 50 or 250 clips. No. 7/16" - 1/2": 250-pieces No. 19/32" - 5/8": 250-pieces No. 7/16" - 1/2" -50: 50-pieces No. 19/32" - 5/8" -50: 50-pieces