Its a Kfactory superflexible antenna and mount. i have a one on my rc18t to.
Yes im using the battery cups serum, they work well, but were quite hard to find.
Also thats a spektrum MICRO receiver. Its a very smart little bit of kit.
Serum you may be interested in my next truck. Im building an alloy / carbon twin lehner 1020/13 powerd mini lst. 2 Quark 33 pros. 2 Flightpowers. Im going to have all the alloy parts reanodised bright orange.