Kodak's Professional T-MAX 400 is a continuous-tone panchromatic black-and-white negative film especially useful for photographing dimly lighted subjects or fast action, for extending flash distance range, and for photographing subjects that require good depth of field and fast shutter speeds with maximum image quality biomedical work, especially when fluorescent photography is required. It has high speed (ISO 400/27° in most developers), very high sharpness, very fine grain, and very high resolving power; it allows a high degree of enlargement. 
 
It offer high efficiency, multi-zone KODAK T-GRAIN Emulsion, also optimized light filtration technology.
Allowing for greater enlargement due to the fine grain 400-speed black-and-white film