I tried using different models of Injectors with different blades including 1. Schick Injector from China that I bought from Amazon. 2. Ted Pella and some others. Whichever blade and injector I use it just not give me smooth shave, it feels like the blade is not sharp at all. There is no issue with the razor or uneven blade gap because I got few NIB injectors. So my question which is the sharpest blade for injector? Also I got a twin blade NIB injector or BST, are these twin blades still in production?