This is a Wenda Solar 12V 40Ah rechargeable solar battery, model 6FM-40AH.
Key Technical Specifications
Voltage: 12 Volts
Capacity: 40 Ampere-hours (Ah) at a 20-hour discharge rate (20HR)
Type: Valve-Regulated Lead-Acid (VRLA) / Sealed Lead-Acid (SLA)
Technology: Manufactured to German standards, typical of deep-cycle gel or AGM technology optimized for slow, steady discharge.