Ilford Delta 400 is a medium-speed black-and-white film which provides an alternative to HP5+ if you are looking for a similar film speed but want slightly higher sharpness and a slightly different tonality and grain structure. The Delta films are newer formulations than films like HP5+ and FP4+ and we encourage photographers to try a variety of black-and-white options so that they can find one that matches their desired aesthetic. 
 
We recommend rating Delta 400 at box speed or slightly lower if you like slightly stronger contrast.