High cell efficiency with quality silicon materials for long-term output stability and reliability.Strict quality control ensures stability and reliability, 23 total testing procedure to carry out quality control High transmittance low iron tempered glass with enhanced rigidity and impact resistance Usein play Type: 300 W solar panel Tolerance: +/- 5% SLA Battery voltage: 18 V Solar cell type: Monocrystalline Open circuit voltage (Voc): 18 V Maximum system voltage: 18 V CoefficientTempered Isc?: (010+/- 0.01) %/C Tempered Coefficient of Voc?: - (0.38 +/-0.01) %/C Tempered Power Coefficient Voc?: -0.47?%/C Temperature range: -40 Celsius to +80 Celsius Color: black Material: Monocrystalline silicon Size: 280?x?380?x?2.5?mm Package contents: 2 x 300W solar panel, 1 x 60A solar controller, 2 sets x connector cover, 1 x English manual. Only the above package content, othersProducts are not included.The allowable measurement error is +/- 1-3 cm.