I purchased these little tiles for two reasons: a) to partially fill in the gaps left on the wall after applying large-format acoustic panels, b) to glue them to the ceiling to avoid putting large-format panels there.
After they were delivered, I discovered yet another important value they'd bring in the studio - aesthetics. They look great and provide a great contrast to the standard studio gray and they match blue elements on the carpet and some of my equipment - Peterson Strobostomp tuner, Roland's GR-55 guitar synth...
Anyway... application.
I created a long 6-piece strip on the wall opposite the speakers to divide 6 large wave-pattern panels right in the middle. With the 'firing wall' covered, I'll use large panels more sparingly and use the Wedges to part-fill in the gaps.
They're thick so they should do a nice job to absorbing most of indirect sound waves and/or secondary reflections - which I guess is their primary purpose.
Also, they are really light so the application on the ceiling seems ideal.
Despite what suggested by the product images, I would advice against using them to cover large areas as primary absorbers, as they're really small but would be perfect for application in vocal booth and such.
An interesting note: the panels may appear to be of different shades of blue when looked at from an angle. This is an optical illusion caused by the way the panels are cut and formed. Turn one panel upside-down and you'll see they're perfectly matching.
I suggest that you align the panels before you glue them to the wall to make sure they appear to have the same color.
There's one little detail I didn't like - the foam is rather softish and fluffy, for example compared to the foam used on Thomann's t.akustik HiLo-N40. It probably doesn't affect its properties, but you may want to exercise more care handling the tiles and moving close to them.
I used Thomann's t.akustik Contact Glue to attach the tiles to the wall.