FUKURO-YARI 袋槍 Rare style Japanese Spear, Edo period mumei

We'd like to introduce the Sankaku Fukuro Yari.
A Yari with a cylindrical tang like this is called a Fukuro Yari.

The tang of the blade is shaped like a tube and is attached to a stick when in use.
The tang of a normal spear is inserted into a hole in the stick,
but with a Fukuro-Yari, you can simply attach it to the stick and complete the spear instantly.
It seems that this was devised because spear handles were prone to breaking.

This Yari has a Mekugiana with an iron Mekugi stuck in it.

Signature : Mumei (Unsigned)
Nagasa : 97mm (3.82 in.) 
Sori : 0mm (0.0 in.) 
Total length : 330mm (12.99 in.) 
Motohaba : 18.8mm (0.74 in.) 
Sakihaba : 14.4mm (0.57 in.) 
Motokasane : 12.1mm (0.48 in.) 
Sakikasane : 6.9mm (0.27 in.) 
Blade Weight : 200g
Total Weight : 244g