Citel DS250VG-300 SPD, unipolar, type 1+2+3, 230/400VProduct Overview The DS250VG 300 is an extreme duty Type 1+2+3 single pole AC surge protector designed to protect electrical installations at the service entrance in high lightning density areas. This heavy duty SPD features patented VG hybrid technology combining metal oxide varistors with gas filled spark gaps to handle very high surge currents up to 25kA on 10 350s impulse, making it particularly suitable for buildings equipped with lightning rods