it may seem expensive but it has a ten year warranty and pay for its self over time.
GemOro Commercial-Duty UltraSonic
(10 Year Limited Warranty)
The GemOro is a commercial-duty unit designed for professional treasure hunters that clean lots of jewelry, coins & relics and offers the best warranty in the industry. The GemOro Powerful UltraSonic's are making a big splash. They're the best on the market, with features & benefits you won't find anywhere else. The key to powerful ultrasonic cleaning is the transducers. GemOro's powerful transducers give you the cavitations to clean even the toughest dirt, rouge, Tripoli, grease, casting investment and more. So durable, they're backed by a 10-year warranty. GemOro's special backed-on Mini-tex paint finish, all-metal construction, and stainless steel tanks resist rust and damage from harsh chemicals and heat, insuring years of use. GemOro's auto-load self-tuning constantly adjusts to maximum output voltage and load voltage to maintain consistent cavitations and cleaning, regardless of load and liquid levels. With GemOro Powerful UltraSonic's, you'll always get more power, more warranty and less cost.
Features: . Custom high-performance transducers that convert electrical energy to ultrasonic sound waves . 10 year limited warranty . cover, on/off switch, for personal or countertop use . capacity: 1-pint, tank: 6x3.25x2 , Watts: 25, Weight: 4lbs.
http://www.kellycodetectors.com/accessories/jewelrycleaners.htm