7mm(Very Suitable and good for 6mm synchronous belt) Diameter of Bore 8mm Flange Double Material Aluminium Setscrews M4
Pitch 2mm Width 6mm Length 5M Material Fiber Reinforced Rubber Color Black
Please note, this is 8mm bore pulley. These pulleys can be used in Ultimaker, Ditto or other 3D Pinter designs with similar kinematics. One Aluminum GT2 Pulley and one Allen key. Please see the drawing for dimensions and calculated steps per mm, for your 3D printer firmware parameters.
For 3D Printing applications, GT2 2mm belt system works better than T5, T2.5, it gives better smoothness and accuracy of positioning, resulting in better printing quality.