Item Type: 3D Printer M4 Extruder Kit Material: Brass, stainless steel. Product Specifications: 2 x Synchronized Wheel 2 x Extrusion Wheel 2 x Miniature Bearing 2 x Unilateral Flange Bearing 5 x Brass Insert Nut 1 x Short Pin 1 x Long Pin 1 x Pneumatic Connector 1 x Closed Loop Timing Belt 2 x Orange Small Snap 1 x blue accessory 1 x Spring Bolt 12 x Screw 3 x Washer 1 x Sticker Kit (3pcs) 1 x Storage Box Package List 2 x Synchronized Wheel 2 x Extrusion Wheel 2 x Miniature Bearing 2 x Unilateral Flange Bearing 5 x Brass Insert Nut 1 x Short Pin 1 x Long Pin 1 x Pneumatic Connector 1 x Closed Loop Timing Belt 2 x Orange Small Snap 1 x Blue Accessory 1 x Spring Bolt 12 x Screw 3 x Washer 1 x Sticker Kit (3pcs) 1 x Storage Box Pay attention to the correct operation. 1Better Effects: Ensuring smoother feeding of filament, this extruder kit enables good printing effects and high efficiency. 2Reliable Works: Large torsion meshing gears promises no material slipping and easy adjustment as well, stable and reliable. 337Pcs in Total: Includes 37pcs accessory, such as synchronized wheel, extrusion wheel, miniature bearing and so on. 4Good Materials: Combining high quality brass and stainless steel materials, not likely for break and very durable for uses. 5Easy to Install: Thanks to the light weight and compact size, the simple installation can be quickly completed in minutes.