Dr. Biswaroop Roy Chowdhury launched his book’ How to build a Super Specialty Home Hospital‘ by using world’s largest screwdriver at the Oxford Book Store, Connaught Place on April 20,2011 . The Largest Screwdriver measures 89.2 Inches and it has an acrylic handle that measures 9.5 Inches at its widest point and is 28 Inches long.The steel shaft is 3.5 Inches thick and projects a further 61.2 Inches making the overall length as 89.2 Inches .