ITEM NAME:Alloy Anti-Collision Protection Wheel Accessories for Dji Robomaster S1 Rob E4F5 Alloy Anti-Collision Protection Wheel Accessories for Dji Robomaster S1 Rob E4F5 Wheel connector only, the product doesn't include RoboMaster S1 robot. Engraving with Aluminum Alloy CNC, Anodizing. Upgraded aluminum material makes the properties more reliable. Aviation aluminum is light and has high torsional rigidity. Easy to Install, Durable. colour: red Material: Aluminum Alloy size: 3.9cm Package Contents: 1 x Wheel Connector.Wheel connector only, the product doesn't include RoboMaster S1 robot. Engraving with Aluminum Alloy CNC, Anodizing. Material: Aluminum Alloy. 1 x Wheel Connector.