I have had a couple of ultrasonic jewelry cleaners over the years, but NOTHING COMPARES TO THIS PROFESSIONAL CLEANING MACHING!!! The GARVEE 6L Ultrasonic Cleaner, 40kHz Professional Ultrasonic Cleaning Machine with Digital Timer and Heater with Stainless Steel Basket is a most impressive machine. It's durability, versatility and cleaning performance are second to none. You could fit everything but the kitchen sink in there as well, haha.This is seriously the most versatile cleaning machine that I have ever seen!!! This ultrasonic cleaning machine works wonders for reaching deep into eyeglasses, watch parts, and headphone filters to remove dust and grease. It works great for dentures and contact lens cases. It cleans silver jewelry and small mechanical parts by removing oxidation and oil without surface damage. It effectively cleans metals, plastics, and delicate items without causing abrasion.This machine is continuously blowing my mind with how well it works. What impressed me the most was the job that it did on a set of antique silverware that I had put away. It had been my grandmother's. It was very badly tarnished and oxidized with age, and polishing it by hand would have been a painstakingly-tedious chore. It was a chore that I had been putting off for many years. I packed up the silverware and into the machine it went. I let this machine run for a full 30-minute cycle, and voilá, the silverware was sparking clean and restored to its former grandeur. I did not think it would have been possible to do this good of a job by hand. Similarly, this machine does a SPECTACULAR JOB on our eyeglasses. It really gets all up in there, reaching deep into the eyeglasses to remove every bit of dust and grease. We really enjoy wearing our sparkling-clean eyeglasses:-)The GARVEE 6L Ultrasonic Cleaner meets U.S. standards for electromagnetic interference and is certified by the FCC (Federal Communications Commission). It also meets European safety, health, and environmental requirements and is CE certified. It is RoHS compliant with restrictions on hazardous substances (limits use of lead, mercury, cadmium, and other harmful materials), and UL-certified by Underwriters Laboratories, one of the most recognized U.S. safety certification organizations for electrical products. These certifications indicate it has been tested for electrical safety, electromagnetic compatibility, and restricted hazardous materials, thus giving a solid level of confidence for home and professional use.This machine is worth its weight in gold (or silver, haha). It has already paid for itself by saving me the time that I would have spent doing tedious cleaning jobs. This is an excellent ultrasonic cleaner that is easy to use and cleans amazingly well. Instructions are included for easy reference. This ultrasonic cleaner gets into all the nooks and crannies. Dirt can't hide from this machine. I highly recommend it!!!