The V520 desktop comes in a 15L chassis, which is 25% smaller than a traditional tower but with the same storage capacity With forward-facing USB ports (4 x USB 3.0), the V520 lets you connect other devices for charging or transferring data, quickly and easily The V520 tower includes the Lenovo Companion app, your one-stop guide to maximizing system performance V520 tower includes Trusted Platform Module or TPM, hardwired-in The 500GB HDD offers you the freedom to store all your professional and personal content