2mm to 4mm Coupling Hub Please allow 4-6 days processing before ship out. For gearmotors or similar motors, we don’t ship using epacket and will use regular shipping if needed. Please note that regular shipping like singapore post might take 45-60 days to deliver, epacket 20 -35 days to deliver Thank you for understanding. » All Products » 2mm to 4mm Coupling Hub This copper coupler can be used for connection of 2mm to 4mm shafts of RC toys, boats and helicopters. SKU: OTH27407972788 Price: 0.99 $ Product in stock SSL Certificate Quantity Updating cart... This copper coupler can be used for connection of 2mm to 4mm shafts of RC toys, boats and helicopters. Specifications Length: 20 mm Material: Brass Related Products M2x4 mm Screw + Nut (30 pcs pack) JGB37-520 DC Gearmotor (61 RPM at 6 V) Proximity E3D v5 3D Printer Head (0.2 mm nozzle, 3 mm filament) 3×18650 Battery Holder with Wires JGA25-310 DC Gearmotor (795 RPM at 6 V)