This drop in food warmer us used but has been cleaned and tested. There are some scuffs and scratches on it from use. One of the red lights are missing on the control panel. Cut out dimensions are 27.25"L x 23"W. 

some information from online:

Keep your most popular foods hot and ready to serve throughout the day with the Vollrath 36399 modular drop in two compartment hot food well! This food well features two compartments that can each hold a full size 12" x 20" food pan for maximum capacity (not included). Its infinite controls make it easy to adjust temperature independently in each well, and the standard 1/2" drain and ball valve ensure water and runoff is siphoned away for effortless sanitation. For outstanding durability, the entire unit is made of heavy gauge stainless steel.

This hot food well is insulated on all sides, between wells, and below the element with fiber insulation to help you save on energy costs, and its remote control panel can be mounted separately from the well for easy use. The included adjustable mounting clips are compatible with counters up to 3" thick, and thanks to its flush-mount flange, this food well will install seamlessly into your countertops.

Overall Dimensions:
Width: 28 1/4"
Depth: 26"
Height: 15"