It was this one, or something very similar
on ebay - Professional Ultrasonic Cleaner 6L - I don't know if the 60Hz would make any difference. This one works fine at 40Hz
http://www.ebay.co.uk/itm/Professional-Ultrasonic-Cleaner-6L-with-heating-drain-Free-ss-basket-and-cover-/350539470594?pt=UK_Health_Beauty_Tattoos_BodyArt_SM&hash=item519dc7d702
on ebay - Professional Ultrasonic Cleaner 6L - I don't know if the 60Hz would make any difference. This one works fine at 40Hz
http://www.ebay.co.uk/itm/Professional-Ultrasonic-Cleaner-6L-with-heating-drain-Free-ss-basket-and-cover-/350539470594?pt=UK_Health_Beauty_Tattoos_BodyArt_SM&hash=item519dc7d702