Here comes the replacement 4mm arms for ZMRX-210 mini quad frame, it will make you worry free with the flying of this carbon fiber mini quad frame. The arms are also suitable for your mini quad DIY. Price is for two arms, so buy as many as you need.Specifications:Thickness: 4mmLength: 119mmQuantity: 2 pcs/kitSuitable for ZMR-X210Before Ordering: 210mm and 280mm arm means the body diagonal size.Update History: 1. Update on March 28th, 2016: Here comes the spare parts for ZMR-X210. You can order what you need by yourself, thank you.2. Update on April 21st, 2016: Here comes the extended arms 280mm for ZMR-X210. With this arm, you can install 7 inch propeller to your ZMR-X210.