Regarding original flashlight:

Stainless steel head, tail and pocket clip.
https://www.fenix-store.com/popup_image.php?pID=1935&image=1

Features:
Made of durable aircraft grade aluminum
…
Diameter (head): 0.55 in
Length: 5.9 in
https://www.fenix-store.com/product_info.php?cPath=22_419&products_id=1935

Besides it's stated usefulness, it sounds sturdier than a Montblanc as a yawara stick/Kubotan.

Multipurpose.