We bought one unit for the Whirlpool dryer. Our washer is top loader. I did find the unit when built and dryer on it was very sturdy. I did find the dimensions were a bit off which caused me to assemble it with the flat top up and not with the dryer inside the edges. Actual outside dimensions are 27\" wide x 28\" deep. Our dryer feet were 27 1/2\" side to side so we had to use the flat side up on the tray. I would not use the flat side up on a washer. I would be afraid the washer would vibrate off the stool. I used my own tools 10mm open end wrench and a 4mm allen wrench. I got tired of trying to get the 10mm wrench in there so I opted to use a 10mm socket with an extension. The unit seems to be power coated so some of the holes are a bit tight to get the screws pushed thru. But let me say we are very happy with the stool. Drawer works perfect and it looks good. Something to keep in mind, we took the feet off the dryer to make things look good. Not sure how that will affect also using one with a washer next to it, height wise, just saying. Since we did the flat top I put the screw heads out in the front to make my wife happy about the look off the unit.