For sale: 5th wheels / muskegon, mi description: the 2012 infinity 3870fk is a fifth wheel that has five slides and a front kitchen. The rear of this model has king bed. A rear bathroom with a shower, sink and toilet lead into the central living area that holds two recliners and a large sofa. The front kitchen consists of a refrigerator, double sink, an island counter, stove, microwave and a dinette. Features: ac specifications: