Item #70227 - TDTB. This toolbox can be used as an under mount toolbox but it is intended to sit on the deck or behind the cab. If you want to mount this tool box under the deck after placing your order email us a request under mount rails.   1/25 scale 91.44 mm Long, 18.28 Deep and 21.36 High, 1/24 scale  95.25 Long, 19.05 Deep and 22.22 High. 1/16 Scale 142.87 Long, 18 Deep and 33.33 High. All measurements are +/- 1.00mm approximately.