1. ZT250-S second generation sprocket wheel seat 
                                                
                                             
                                            
                                         
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                                                        2. ZT310-R 520-42T sprocket 
                                                
                                             
                                            
                                         
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                                                        3. Non-standard nut M10×1.5(Dacromet) 
                                                
                                             
                                            
                                         
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                                                        4. ZT310-R 114 section chain (520 oil seal chain) 
                                                
                                             
                                            
                                         
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                                                        5. ZT310-R1 114 section chain (520 oil seal chain/open type) 
                                                
                                             
                                            
                                         
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                                                        6. ZT310 rear wheel left sleeve φ20×φ30×φ35×17.8 
                                                
                                             
                                            
                                         
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                                                        7. ZT250-S sprocket buffer rubber 
                                                
                                             
                                            
                                         
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                                                        9. GB276 deep groove ball bearing 6205-2RS-C0 
                                                
                                             
                                            
                                         
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