It's time for "Volume 2" of the Boom8 display figures. (Volume 1 was 2 Sonics, as seen on Display figures 7 here at Gear) Following in those classic lines, the next logical figures are (of course) Tails & Knuckles! Because they're teaming up with First4Figures, it's only natural that these small display figures look great & accurate in their classic style.
They did also bother to scale these, which is always great to see. Knuckles is a little bit taller than Sonic & Tails is shorter than everybody else. This will make them look great together on your shelf.

Look at how they have posed Tails' tails, it's 1 up 1 down which is nice to see because it's different than other previous figures (Sometimes both down/joined together to make molding easier/using them to help him stand, etc gimmick stuff with them) Knuckles spikes are also nice & wide and they made the fists big and distinct.

The boxes are similar to the Sonic ones, with big front window & character portraits on the sides. Look at the CG though...usually classic characters are never depicted with CG so Knuckles looks a little strange. These are available in 2018 at the First4Figures website.