Cayce Kerr's heart jumped into his throat Tuesday afternoon as he stood on the 17th tee at the Augusta National Golf Club.

Kerr, the caddy for Fuzzy Zoeller, was preparing to measure how far Ike's Tree stands from the tee on the par-4 hole when he discovered a missing item. Earlier, while waiting on the 15th tee, Kerr and a young lady in the gallery exchanged glances, and he waltzed right off the tee box without his prized possession.

``Wouldn't you know one of those gallery guards had it waiting for me when I walked back up there,'' Kerr said. ``The gods of Augusta were good to me.''

Kerr's cherished object is the newest gizmo on the PGA Tour, a yardage range finder that provides highly accurate measurements through the use of laser optics. It has made PGA Tour caddies very high tech as they prepare for tournaments. The device is considered an outside aid and isn't allowed during tournament play.

The range finder, which resembles a small video camera, is similar to a pair of binoculars. You focus a small circle within the viewing field on an object in the distance, usually a flag stick, water hazard or tree, press a button and in one second an LED readout gives the precise yardage up to 1,000 yards away.

The bill is heavy - from $3,300 for the top-of-the-line Swarovski Optikcq, manufactured in Austria, down to $250 for a lesser model.

``If you're a butcher, your life's work is meat,'' said Kerr, who represents Swarovski on tour after learning about the company from a gallery member one year ago. ``If you're a pro caddy, it's yardage.''

The clients include course architects, instructors, college coaches and players, who give them to their caddies.

By Kerr's count, approximately 32 players in this week's field own one, including defending champion Ben Crenshaw, Arnold Palmer, Ernie Els, Peter Jacobsen, Davis Love III, Sandy Lyle (the first to use one on tour), Tom Watson, Zoeller and John Daly. Daly, in fact, owns two.

Raymond Floyd purchased one on Tuesday and Kerr had business cards from other prominent golf figures, including Karsten Solheim and Greg Norman, in his money clip on Tuesday. Johnny Miller of NBC and Peter Kostis of CBS use them for golf telecasts. Kerr said he has sold more than 80.

``Caddies can really be precise with giving yardage and checking it against the (yardage) book,'' said Crenshaw. ``And I think they have fun with it.

``I also use mine for working a golf course. If you've got a raw piece of property, you can line it up on a stake and figure out if you want to put a bunker 210 yards or 250 yards from that point. It's really quite helpful.''

Kerr, who said Augusta National's yardage book was entirely accurate, said he can now answer with confidence when Zoeller asks for a peculiar yardage.

``If my man is in the woods and asks how far it is from the woods to a water hazard, I can't say, `Oh, about 170 to 190 yards,'' Kerr said. ``With this range finder, I can say exactly how far it is. If he asks, `Are you sure?' - there's no doubt in my answer now.''