Do you still have the packaging the roller bearings came in ?

I'm questioning the 400lb rating, as the higher quality Stainless Steel 1" roller bearings are rated at 110lb each and they specifically list that the 1" roller bearing, rides on internal 1/8" bearings (like shown in the cross-section drawing for the stainless steel roller bearings).

The two chinese-made 16pc 1" roller bearing kits listed on Amazon use high-carbon steel versus stainless steel in the 12pc kit, and have a hole drilled in the bottom retaining plate where those 1/8" internal roller bearings should be. Bearings and holes don't mix well...

This suggests the cheaper chinese-made high-carbon roller balls are just that - cheaper chinese-made...

And if you read the Rev Trainer's actual product description, it states this:

"Note: The rollers have a sponge washer inside them that may work its way out of the roller. The roller moves more freely without the washer and losing the washer should not cause any issues to the workings of the Rev Trainer."