That is a plane finder made by Tettra. When attached to a spare channel, this plane finder buzz when remotely switch on, to ease the pilot to find the plane or its remains. Another design have battery power indicator too so when the battery is below 4.7V the buzzer sound too. A gimmick device.

As to the cleaniness of the plane, this is common amongst most Japanese pilots. They take pride in keeping clean and tidy on every part of their plane. Also patternships built by Japanese professionals have second to none quality, everything is so tidy and clean, and they have many "secrets" into building a plane.

An Austral XX built by Mr. Naruke easy fetch US$10K, but even one wants to buy, the waiting list is usually one year, and the prospective owner have to be "preapproved" by Mr. Naruke before getting into this list...