The invention provides a magnetorheological device employing narrow design gap and containing a magnetic-responsive composition exhibiting reduced off-state forces and good performance. Specifically, this invention is directed to a magnetorheological device of defined gap, and employing a magnetic-responsive composition characterized by comprising non-sperical magnetic-responsive particles of average number diameter distribution (d.sub.50) from 6 to 100 microns and at least one friction-reducing additive that reduces the interparticle friction between the magnetic-responsive particles.