Brand new Tripp Lite, power inverter/automatic battery backup. I purchased this and never got around to buying the batteries. I no longer have the box or manuals, but manuals are available online if necessary. I believe these retail for around $225. I'm asking $150 including shipping. I can also meet you locally for $130.

Tripp Lite's Alternative Power System 512 combines the features of an inverter, a battery charger and an expandable UPS to provide mobile or backup power for multiple applications. 500 watts of battery backup provide reliable and economical power for your equipment during blackouts or brownouts. The unit has 2 outlets and diagnostic LEDs. A switch allows the user to select between "off automatic" or "charge only settings". Regulated output voltage and frequency control provide operating stability.

500 watts of battery backup provide trustworthy and economical power for your tank and equipment during blackout or brownouts.

tripp lite - Tripp Lite automatic power inverter APS-512