4 X Solar Module Bracket PV Mounting Rail Set, Fixing Mid/End Clamp for Caravans
For 2 solar panels, you need 6x rail + 4x end clamp + 2x centre clamp. For 3 solar panels, you need 8x rail + 4x end clamp + 4x centre clamp. For 4 solar panels, you need 10x rail + 4x end clamp + 6x centre clamp.