Instructions say to use in trans for 1000 miles, drop pan and do a flush. I had to drive another week as the truck is my daily driver. Instructions also say if you have used additives in the transmission in the past go ahead and go to 1500 miles to let the product do more work. Anyway this is the pan drop. Amazing amount of silver stuff floating in the liquid and definately ferrous huh. The magnet is a flat piece, at first it looked like it had raised channels on it. NOPE! Yikes. Truck has 80,000 miles and unknown if it's been serviced in the past.