In 1966, disc brakes were starting to be offered on a wide variety of vehicles. The problem was that fixed opposed piston calipers were very heavy and expensive. Also, they were overkill for most common vehicles of the day. Fixed opposed piston calipers equalized the pressure on the pads hydraulically. The less expensive solution was to use a single piston and equalize the forces mechanically. The brake manufacturers came up with a number of designs before they settled on the traditional caliper floating on guide pins or slides. The first solution was a plate that surrounded the hydraulic piston and rotor. While the Bendix K Series did not make it, many Asian and European manufacturers used this type of caliper until the late 1980s on cars like the Datsun 510 and Saab 900. These systems worked because they had mass to dampen vibration and the ability to compensate for large amounts of lateral runout and DTV.