I have bought these new tonfas today.
The tonfa is one of those weapons originally used on the Ryukyu Islands (of which Okinawa is one) in the martial arts known to us as Kobudo and Kobujutsu.
To me, these weapons are synonym with traditional Karate, which I regard as an unarmed form of Kobudo. If you really want to know why I say this you can email me at email@example.com for the explanation.
This double weapon makes an effective shield with blocking techniques that can be taken directly from karate. Its attacks include thrusts and swinging slashes when the handles are used as pivots. Pommels on the handle and short end allow for even more short range attacks (not seen in the video).
Tonfas today, unlike the traditional version, are made in the fashion of the modern night stick, meaning that the extra handle allows it to be used as a baton. Police training handbooks usually contain arresting and immobilising techniques that can be executed with the night stick.