Amazon.com: Nady MM-242 4 Stereo / 8 Mono Channel Mini Mixer with mono/stereo mode, ¼” Inputs and outputs – battery powered, or use optional AC adapter : Musical Instruments
Pro 4 Stereo / 8 Mono Audio Mini Mixer effect reverberator 1/4 Inputs and outputs - battery powered, or use optional AC adapter - AliExpress
Roland Go:Mixer Pro-X Audio Mixer for Smartphones – Kraft Music
ammoon AGE03 5-Channel Mini Mic-Line Mixing Console Mixer with USB Audio Interface Built-in Echo Effect USB Powered for Recording DJ Network Live Broadcast Karaoke - Walmart.com
AMERICAN RECORDER 4 Channel, Battery Powered Mini Mixer - Walmart.com