Brickset
“This is fun. This is the largest 'classic brick' magnet set and has 14 bricks, all 4 x 2, and all magnetised. The magnets are set into the three tubes in the back of each brick, so they still can be used as regular bricks. The only exception is that you can not offset a... More smaller brick in the center of the underside of the magnet bricks, as the magnets are flush with the bottom. Interestingly, the magnets have been set with the same polarity, so the bricks click together with no problems.”
Full review at brickset.com