Add two 25 sata hdds up to 15mm in height to your mac or pc through thunderbolt with a well ventilated storage solution that helps keep your drives running cool the s252smtb3 2 bay enclosure features thunderbolt technology that maximizes the performance of your external drives by enabling you to connect two 25 sata iiiiii hard drives hdd or solid state drives ssd to your mac or pc using an available thunderbolt port transfer data to and from your external drives faster than eve