With 1x 12cm cooling fan install slot. This hard drive cage is designed to fit the space of 3 x 5.25-inch CD-ROM slots. It supports up to 5 x 3.5-inch hard drives, allowing easy hard drive expansion. Please check the dimensions and ensure your PC case has enough space for installation. Compatible with PC cases that have a flat CD-ROM slot panel or bracket-type CD-ROM slot. Some PC cases with special designs may not support this hard drive rack; in such cases, modification or external use may be required. Model Number: HDD Hard Drive Cage Rack. Color: Silver + Black. Material: Plastic + Metal. Package Contents: 1 x HDD Hard Drive Cage Rack, 10 x 3.5-inch HDD Installation Brackets, 8 x Fittings. The package includes only the items listed; other products are not included. Note: Lighting and display settings may cause slight color variations between the image and the actual item. Measurement error is +/- 1-3 cm.