I'm assuming you're referring to the DJI S-800. In that case it's not authentic. See note on the S800 page on DJI's website
In light of the recent event at RCG concerning MS-800 (DJI S-800) clone or counterfeit, DJI takes this seriously. We filed two patents on S-800 (Patent Pending 201120275378.4 201120436743.5) several months ago. Our legal team is the process of contacting RCTimer. We hope this issue can be resolved. However, RCTimer business registration presents a challenge.
At the mean time, there is no evidence RCTimer MS-800 exists since they use photo from DJI website. We would like to ensure our working relationship remains strong during this time awaiting legal team result and direction on the matter.
DJI-Innovations has confirmed that DJI S-800 being offered/sold by RCTimer.com under MS-800 is counterfeit copy of the original S-800 despite the use of different product ID. DJI believes it is a danger in using MS-800. DJI will not be held for all liability and will not support any warranty or service in regards to them.
That being said, it looks like it will be a clone of the S-800 just like they've produced clones for the flame wheels. Don't know if it will be "a danger" to use the MS-800, but others have found the RM450 and RM550 to be of good quality.