"Piston calipers" refers to a mechanical component used in braking systems. It uses a piston to squeeze brake pads against a rotor, resulting in friction that slows down or stops a vehicle. Full definition
The braking system was upgraded to dual - piston calipers in the front. (en.wikipedia.org)
The CS comes as standard with cast discs with four - piston calipers at the front, two at the rear and put simply they are not a match for the car's performance. (evo.co.uk)
Behind them are healthy brakes with six - piston calipers up front, four - piston in the rear. (automobilemag.com)