What is esd protection, esd protection equipment, ESD clamping voltage

 PGB1 Series 24 V 0.06 pF Bi-Directional 0603 PulseGuard® ESD Suppressor

https://www.futureelectronics.com/p/electromechanical--circuit-protection--esd-protection/pgb1010603mrhf-littelfuse-3012690