"SK Series" pure sine wave inverters are similiar to the "S Series".  They are designed for heavy-duty use and are microprocessor controlled, but only meet UL/cUL standards and are not fully listed.  They are FCC compliant.  Main difference- "SK Series" has a higher surge rating-designed for high start-up loads. Also available in 24VDC and 48VDC-call for pricing. 

Specifications Model# Input Voltage Output Voltage Dimensions Output Fuse Rating Shipping Weight Lbs. SK3000-112 10.5 ~ 15 VDC 100/110/120 VAC +/- 3% 17.8 x 8.2 x 6.5 3000 Watts n/a 22 lbs Applications Service vehicles Mobile Offices Boats Recreation Vehicles, Camping Telecommunication Field work / Construction sites Solar power systems Emergency backup power Home electronics: TV, VCR, video games Computers, printers Design Features Pure sine wave output(THD <3%) 50/60Hz switch selectable output frequency Input and Output fully isolation design Low power saving mode to conserve energy Loading controlled cooling fan Advanced microprocessor Short-circuit, over-voltage, under-voltage protection over-temperature, over-load protection Meets UL458 (but is not UL listed) Operating Temp. range 0~40C