This is the AirBlade Eclair V2 3" Lite frame. The idea is to build a 3" capable frame that run 4S while staying as light as possible. The frame side plate and backpack is similar to that of the Eclair 2" and 2.5". The only difference is the longer arm. Given that the arm length differences is minimal, this maintain a similar weight to a 2" but now have the power of 3" on 4S. You get the picture!

The Tattu 450mah 4S is 55g (not pictured) and this setup lasts about 3-3.5 minutes ripping.