These nicely crafted top mount spacers will lift the shock/spring assembly by 8mm and 10.4mm lift is expected to the car ride height. The 8mm version available should work with strut braces. Being made from duralumin they are very strong, but lightweight with less than 100g per corner.
You will need them, if you have coilovers or springs, that are too low, even in their highest position. The top mount spacers are the way to keep them by adding the mm's missing to freely pass the speedbumps on the way home.
They are sold as pairs (for an axle), you will need to order 2 sets for all four corners.