This is a used step it will need lube it has scratches and scuffs and glue on base 

10.75" tall with slide 

Bottom base is 9 inches wide 9 inches deep the bolt holes are at 7 inches side to side and front to back

The top base is 10 inches wide 13 inches deep the slide bolt pattern 8 inches wide and 11 1/2 inches deep

When a seat is mounted the forward and backslide handle would be to the front and the handle to turn it would be to your right