Retainer: Plastic UL 94V-0. Easy to install, no need to remove fan or guard. Designed for low air resistance. Media. PU foam 30 or 45 PPI. Easy and simple to clean and change. Reduces external fan noise. Guard: Plastic UL 94V-0 UL 0.25" spacing (6.3 mm). Decreases noise level while minimizing low air restriction. Features: Available in Sizes from 40-172 mm Snap-On Feature Makes Changing Media Easy Quick and Easy Installation Custom Designs on Request Specifications: Dimensions : 123.7 mm...