A few years ago, Black Belt magazine ran an article on the "Manri-Key".   Essentially, a dog chain with split rings on each end, and a bunch of keys attached to same for the weights.

I played with one for a bit, quite effective.  And you could always claim it's your key-ring....

Of course, many of us naughty old coppers know all about such things; padlocks have been a motorcycle-gang favorite weapon for many years.

Interestingly, after I read the article mentioned above, I noticed several of our housekeeping staff walking around with arrangements of keys like that.   As far as I could tell, it was just coincidence; none of them seemed to have any idea you could use the thing as a weapon.

Thanks for the book, Stenny.

Hi Fritz, long time no see! I am glad you like the KWJ. I hope you will mend the e-mail soon!

If you would want to buy one, watch out for the joining of chain and handles - this part is very, very weak on many commercial-made manrikigusaris and can give you a nasty surprise by breaking in the worst possible moment.

Does it matter if the chain is a choke chain that is designed to lay flat on a dog's neck? I found one that would be about the length of my arm if I used Masterlock handles.

This is true . Choke chains are desiged to lie flat and not cause bruises . Number 3 machine chain is best . I can assure you it hurts real good.  OWWW ! : )

it helps i'm sure but that isn't stopping me swinging a weighted rope around in the same manner