As a member over at the M&P forum, I entered a monthly contest and won! My prize was a new KA-BAR TDI. I had never heard about this knife until I won it so decided to do a little research. The sheath can be converted to RH or LH and from what I gather, it's designed to be worn on your off-hand side as a backup if your pistol becomes disabled or lost. It's about a $30 knife most places.
As in the review, the handle seems a little small in my hand but I have big hands and if it were bigger, it would be harder to conceal. The knife angle - it is designed to be used defensively in a punch/stab motion.
If you're interested, here is a review of the knife:
Ka-Bar TDI: On the Street at Officer.com