3-in-4 2.5"/3.5" SAS/SATA III Storage Kit ?Designed as standard mounting hole for converting 5.25" drive bay ?2.5"/3.5" hot-swap trays x 4, converts to 5.25" drive bay x 3 ?Supports SAS / SATA III HDD ?The front indicators warn of fan failure or unusual temperature spikes ?Detachable 90mm PWM rear cooling fan