The dewalt dcs391 premium circular saw with an intelligent trigger allowing total control over all applications it has a powerful and highly efficient pm58 fan cooled motor with replaceable brushes which delivers up to 3700 rotations per minute for a fast cutting action it has a spindle lock for quick and easy blade change it has an extremely durable tool design including a cast magnesium base which allows repetitive accurate cuts with an ergonomic handle set with rubber overmold the saw provide