I always like a challenge but this was too easy to find online. Did you really look?
Beli Tongkat Pentungan Pemukul Polisi Security BATON Stick POLICE Pendek
https://tokopedia.link/ALxKN7m5dW di toko MR MIYAMOTO Rp55.000 di Tokopedia Sekarang!
Oh and just search by tongkat security or baton security or similar. Lots and lots to choose from
Please be careful about the legality of carrying and owning "weapons" and whether collapsible batons fall under the category.