Look at it this way, If you sent 5 employees to the clinic to get drug tested if everything went as expected they may be in and out of clinic in 2 hours. Not bad but what if you have a couple slackers dragging the 3 hour limit to its end. That would be 15 man hours lost just for five employees. We can test 40 in 3 hours all things said. Give us a try call me. 918-946-4339.