There are many inverters.. They fall into two by two groups
1: Stand alone or "In-line" your 3.0 is an Inline
2: MSW/TSW... I believe yours is a TSW.
NOTE: If you are buying an inverter, even though they are more expensive I suggest a TSW (True Sine Wave or Pure Sine Wave) as the list of things that won't work with a 3,000 watt TSW inverter is: Anything needing more than 3,000 watts.
The list with a MSW inverter is much, much, longer.
In all cases, an In-Line inverter will have AC-IN and AC-out connections, it will also have battery connections.
What is the difference between one and another.
Some have a remote display panel.. This likely will be different,, Some are larger, smaller, wider, or have connections in different locations.. USUALLY wires can be re-routed easily...
Some the charger module has greater or lesser programmability or ability or quality..
But from an electronics viewpoint, you can use any 3,000 watt IN-LINE True Sine wave inverter to replace it... Just may need to drill a few screw holes is all.
I can not recommend a replacement brand or model because frankly... Far too many good ones out there.. In this size (over 1,000 watt) most all of 'em are fairly good to excellent.
Home is where I park it!