Capacitors C1 and C2 help protect the FETs during an ESD event. The use of two devices ensures normal operation if one of them becomes shorted. In order to have good ESD protection, the copper trace inductance of the capacitor leads must be designed to be as short and wide as possible. Ensure that the voltage rating of both C1 and C2 are adequate to hold off the applied voltage if one of the capacitors becomes shorted.