t.akustik Wedges 30

Looks better in the picture, but for the price they surely are better quality than the "usual" plain grey practice-space pyramid foam.
I used them in combo with DIY bass trap panels and the t.akustik Highline CBT1 angle bass traps. They help with creating a certain look and I noticed a slight improvement in the mid-high reflections. To be honest I think the bass traps are doing the heavy lifting here, but nonetheless I feel like recommending if you care about that 0,2% extra when it comes to sound treating your room.
If not just save up and buy something from the same line, but pricier!