Buy an excellent study material for class 12th students in Biology and Chemistry. Use this external hard drive to learn at your own place. This external hard drive contains: 267 hours of 513 video parts with 128 GB size.Supplemented with 1312 pages and 59 MB size of e- study material. It covers Biology and Chemistry of XII standard CBSE and competitive exams like AIPMT and AIIMS. Validity: 1 year. Compatible OS: Windows XP/7/8 , License: Single Machine with Windows Operating System.