Freight cars (and some passenger cars like multiple-unit cars whose traction motors do not yield room on axles to allow the placement of disk brakes) are equipped with "clasp brakes" which directly grab the rolling surface of the wheels (much like the old horse buggy brakes of yesteryear). Such brakes are an external-shoe drum brake; but unlike band brakes and many internal-shoe drum brakes, there is no self-assist/self-servo effect, and so they are far less susceptible to locking than self-assist brakes. Due to high stiffness and relatively low power, these clasp brakes are even less prone to lockup than many disc brakes, and so freight cars using them are not equipped with anti-lock systems.