I was given one of those by a Korean friend years ago. He told me at the time, “Be very careful, this can cut you really bad!”
The first time I used it, I almost lost a thumb-tip.
I’ve got two in the house that I’ve never used since. Sometimes I see chefs on TV using them without a guard. Gives me the absolute willies :-)
-JT
Bought a Faberware mandolin at wallyworld for $20 this week. Works well.