The likes of greg666hell

HK47K upper for JM12 AK74U

US$ 2.84

Airsoft AUG A3 rail kit

US$ 5.86

MOE Grip

Free

AMB-17 AEG full build kit

US$ 41.02

Airsoft Zenitco RK9 AR GRIP

US$ 4.69

MCX-15 handguard - Double Eagle - integrated Osprey

Open priced

TAVOR TR21 M-LOK HANDGUARD PRESSURE

US$ 21.97

MP5 to AR kit（Gelsoft/aitsoft）（lee sporting type）

US$ 8.51