Bahco ERGO Oval Shaped Handle for Flat & Half-Round Files. Developed according to the scientific ERGO process, to reduce muscle tension and the risk of injury. The hard polypropylene core, covered with a thermoplastic elastomer, provides a comfortable non-slip grip, and the handle&rsquos smooth contours fit into the hand naturally. As a safety feature, the handle covers the tang and shoulder completely to prevent the hand from slipping off the handle onto the file blade.