3mm 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 » 3mm to 4mm Coupling Hub This copper coupler can be used for connection of 3mm 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 3mm to 4mm shafts of RC toys, boats and helicopters. Specifications Length: 20 mm Material: Brass Related Products JGA25-310 DC Gearmotor (862 RPM at 12 V) 600W DC-DC Boost Module USB LiPo Battery Charging Cable with 1.25 mm Male Connector JGA25-370 DC Gearmotor (188 RPM at 12 V) 20pcs SOP8/SSOP8 SMD to DIP Adapter