20mm 30mm 40mm round folding arm folio part carbon tube clamp clip adapter connector joint for RC quadcopter multi-rotor drone Material: aluminum Process: CNC machining Colour: Black Folding specifications: supports 20mm, 30mm, and 40mm carbon tubes Hole diameter: 4mm Folding angles: 25mm and 40mm versions fold to approximately 90 degrees; 20mm version folds to approximately 170 degrees and can be folded horizontally or vertically.25mm version: folded outer diameter 29mm, inner diameter 25mm — compatible with carbon tubes having 25mm outer diameter.30mm version: horizontal folding angle approximately 160–170 degrees, inner diameter 30mm — compatible with carbon tubes having 30mm outer diameter.35mm version: outer diameter 35mm — compatible with carbon tubes having 35mm outer diameter.40mm version: folded outer diameter 44mm, inner diameter 40mm — compatible with carbon tubes having 40mm outer diameter.Suitable for Greenery Care multi- multi-rotor drones.