t.akustik nook set big 36

These are very well made and very effective.
They arrive in one big but light box.
They are strong foam but still very light so easy to hang (just make sure to use strong glue because they will fall off otherwise).
There are very effective in killing the low frequencies bouncing around the back wall of my studio. I use them in conjunction with homemade rockwool baffles and EQ Acoustics Classic Wedge Tiles.
I would recommend them as an affordable alternative to an expensive customised absorber/diffuser.
The big set, as opposed to the smaller ones, does take up quite a bit of room as they come out 30cm from the wall so you need to make sure you have room for them.