Perfect for SSP kits, Blitz, DartBox and More! These hex hubs are perfect for mounting wheels or 3D printed custom parts to your motor shafts. Available in 4mm and 6mm bore to fit a wide range of popular gearmotors — including our own Blitz Lite, Blitz Pro, and DartBox Gearmotors. Made from strong yet lightweight 6061 aluminum, at 1/3rd the weight of brass or steel, these hubs will fit in well on almost any bot with direct-driven wheels! There are two extra tapped holes for inserting long set screws or normal M4 x 4mm set screws (included) on the hex side to help secure narrower wheels, gears, pulleys, and more. And unique to these hubs is a precision turned 12mm diameter for adding a bearing (sold here) or bushing support to protect otherwise fragile direct-driven wheel setups. Not sure which bore to choose? Pick the one that matches your motor's output shaft diameter. Both variants share the same hex size and overall dimensions — only the bore differs. CAD Model Download Here (both bores included) Each package contains two (2) hubs and four (4) M4 x 4mm set screws. NOTE: 6mm bore hubs will not work with 4mm shaft motors. For DartBox gearmotors, see our 6mm shaft upgrade kit. Compatible Motors Compatible Motors 4mm Bore: DartBox Viper & Dragon Drive 4mm Gearmotors DartBox Gecko 4mm Servocity Premium Planetary Gear Motor Servocity Econ Spur Gear Motor Rectified Robotics Brushless Gearmotor Botkits 22mm DC Gearmotor Double Geared 25mm Motors Any other 4mm shaft motors! 6mm Bore: Blitz Lite 20mm Brushless Gearmotors Blitz Pro 24mm Brushless Gearmotors DartBox Gecko 6mm DartBox Viper & Dragon with 6mm shaft upgrade kit Repeat Drive Max & Pro Mega Sparks Any other 6mm shaft motors! Specifications Specifications Material: 6061 Aluminum, strong and lightweight Total Length: 18 mm (0.71 in) Weight: