Gemtech 12145 Quickmounts Flash Hider Black Steel with 1/2"-28 tpi Threads & 2.40" OAL for 5.56x45mm NATO AR-Platform $94.05
Kel-Tec PLRSU582 PLR-22 Muzzle Brake Kit Black Steel with 1/2"-28 tpi Threads for 22 LR Kel-Tec PLR-16 $21.79