TW is Total Weight. So if you got a cluster ring with a big .75 rock, that has another four .25 rocks surrounding the big one, you got a 1.75 TW piece.

Our TV died two weeks before Christmas, so I got us a cheap 27" TV to tide us over till I can afford a fancier one.
To my wife - a 1GB hunk o' RAM for her PC.
To the lad - a "gig bag" for his Washburn X10 guitar, and a snowboard.
To my daughter - countless toys & clothes. She'll also be two years old this coming Saturday, and I still gotta get her something for that... Maybe a trike or something.