ESD protection equipment, Electrostatic protection, What is esd protection,

 PGB1 Series 250 V 0.04 pF Bi-Directional 0402 SMT PulseGuard® ESD Suppressor

https://www.futureelectronics.com/p/electromechanical--circuit-protection--esd-protection/pgb1010402kr-littelfuse-6417943