2pcs Coupling Hub for 4 mm Shafts Hello Customers, we would like to inform everyone that we will not be accepting orders until we fix the issue of disappearing shipping cost from your orders. We are still investigating and fixing the settings so that the correct shipping cost will be displayed in every order. Thank you very much for understanding » Gearmotors » Accessories » 2pcs Coupling Hub for 4 mm Shafts This coupling hub allows secure coupling of a variety of mechanisms to 4 mm motor shafts. SKU: JSL13282219971 Price: 9.57 $ Product in stock SSL Certificate Quantity Updating cart... Overview This coupling hub allows secure coupling of a variety of mechanisms to 4 mm motor shafts. Specifications Length: 15.5 mm Inner Diameter: 4 mm Outer Diameter: 22.5 mm Related Products DC Gearmotor and Wheel JGA25-371 DC Gearmotor with Encoder (201 RPM at 12 V) JGA25-370 DC Gearmotor (82 RPM at 12 V) 2pcs DC Motor with Speed Encoder Disk JA12-N20 DC Gearmotor (150 RPM at 6 V)