Safety razor the rectangular dimensions shared by the wedge, standard single-edge, and double-edge blades. The injector, itself, was also the first device intended to reduce the risk of injury from handling blades. The Gillette blade dispenser released in 1947 had the same purpose. The narrow injector blade, as well as the form of the injector razor, also strongly influenced the corresponding details of the subsequently developed cartridge razors. Both injector blades and injector safety razors are still available on the market, from antique stock as well as modern manufacture. The injector blades have also inspired a variety of specialised blades for professional
Straight razor and balance of the razor. A razor is well balanced if when opened it balances about its pivot pin, indicating that the torques about the pivot point, caused by the corresponding weight distributions of the blade and the handle about the pivot pin, counterbalance each other. A well-balanced razor is both safer to handle when open and easier to shave with. The characteristics of each blade type determine the type of recommended uses for each blade as well as their maintenance routines. Each type has its own strengths and weaknesses depending on the requirements of use. Extra hollow blades such