niceeshop(TM) Branch Connectors Solar Pair MC4 Connectors Y Connector MMF FFM for PV / Photovoltaic System Plus HQRP Coaster,Black Material: tinned copper+insulated PPO;Size:15x10x1cm/5.9x3.9x0.39inch Compatible with MC4 connectors Also known as MC4 T connectors Contact Material: Copper, silver plated Flame Class: UL94-V0 or UL94-5VA One FFM; one MMF Withstanding voltage: 1000V DC(TUV), 600V(UL)