Specification:                                                                                 
Diameter: 440mm;　                                                                      
External Diameter: 720mm;                                                                        
Thickness: 105mm;　
Buoyancy: ≧14.5N;                                                                           

Product description:                                                               
Plastic color stability, anti-aging;                                                    
Adopt high- density polyethylene as shell;                                            
 Inside filling high-density polyurethane closed-cell foam;