Specification: Type: Hard Disk Shock Absorber Bracket Model: 3.5" to 5.25" Material: Metal Bracket + Rubber Nails Color: Blue Size: 145x123x30mm Package includes: 1 x Hard Disk Shock Absorber Bracket + 6 x Rubber Nail + 2 x Fixed Metal Strip + 8 x Mounting Screws Product features: Optical drive to hard disk rack, movable silica gel to reduce vibration and noise Purpose: Suitable for most cases with optical drive, and one shelf occupies one optical drive. Any 5.25 inch front bracket can be placed. Complete spare parts are included for easy installation.