Attention all foreign spies. If you want to know what the Air Force's supersecret Stealth fighter jet looks like, try your local toy store.

A model of the F-19 Stealth -- an aircraft so sensitive the Pentagon will not even say it exists -- is available for $9.95 at toy stores across the country. And according to its manufacturer, Testor Corp. of Rockford, Ill., it's quickly become the hottest selling model in the country, raising new questions on Capitol Hill about the rigid secrecy surrounding the supposedly "invisible" aircraft.

"It's bizarre," says Rep. Ron Wyden (D-Ore.), who held up a copy of the Stealth model during a House subcommittee on oversight and investigations hearing this week. "What I, as a member of Congress, am not even allowed to see is now ending up in model packages."

The secrecy of Stealth got fresh scrutiny at the hearing when the aircraft's builder, Lockheed Corp., acknowledged that it cannot locate more than 1,000 classified documents relating to the program. Subcommittee members were incensed at the potential security breach; they say it shows that so much information about Stealth already has come out that the Pentagon's no-talk policy no longer makes sense.

"As far as the security system on this goes, it's like the old Gertrude Stein quote -- 'there's no there, there,' " Wyden said yesterday. "The fact is the Stealth security system is absurdly easy to penetrate."

The Stealth model drives home the point, he said.

Since the model first hit the market at the end of June, sales have been booming. About 100,000 Stealth kits have been ordered by toy stores already -- three times more than a typical new model plane.

"You've got a little bit of mystery about it -- and that makes it exciting," said Steve Kass, Testor's national field sales manager. "In terms of units sold, this will be the number one selling kit this year."

But Kass said the model gives away no secrets that haven't already been published in a flood of trade press stories. Stealth aircraft are designed to escape detection by enemy radar. But the model doesn't reveal the aircraft's insides, which, according to Kass, is where the real Stealth secrets are.

Moreover, he added, none of the missing Lockheed documents were used in designing the model.

"We're all patriotic, loyal citizens here," Kass said. "Everything we got, you can get out of any library."

According to some experts, that is quite a bit. Bill Sweetman, author of a book on Stealth aircraft, says the model "in size and proportion and quite possibly in overall plan . . . is pretty accurate."

The model also contains a number of details about Stealth technology that the Defense Department never has publicly discussed.

On the side of the model's box is an "F-19 Stealth Fighter Profile." It states that real Stealth jets "operate from remote, top-secret airbases," use laser technology to guide Maverick missiles, and include folding outer wing panels so they can be transported inside Lockheed C-5 Galaxy airplanes.

When asked to comment about the model yesterday, Pentagon spokeswoman Jan Bodanyi refused. "I have nothing to say about this alleged Stealth fighter," she said. "I can't even say there is such a thing."