Sescom Stereo RCA to 3.5mm TRRS Plug Line to Mic SES-IPSUMRCA3
Amazon.com: Headset Buddy Line-Level Audio Adapter with Built in Attenuation for iPhone, Smartphones, Soundboards and Mixers (iPhone-Mic-Line) : Electronics
Amazon.com: Shure A15LA Line Adapter-Converts Balanced Line Level Signals to Microphone Level (50dB Attenuation) : Industrial & Scientific
Headset Buddy Mic-Line Plus - Line-Level Audio + Monitoring Adapter for iPhone & Smartphones
Audio Signal Levels Explained: Mic, Instrument, Line, and Speaker | Black Ghost Audio
Pro Co Sound LMX In-Line Barrel XLR Mic to 1/4" Line Level LMX
Line level to Mic level converter - CircuitLab
impedance - Circuit to Convert Line Level to Mic Level - Electrical Engineering Stack Exchange
Rolls MB15b ProMatch 2-way XLR/RCA line-level converter at Crutchfield
Line Level XLR Microphone Adapter Kit with Lightning to Headphone Adapter - VeriCorder Outlet
impedance - Circuit to Convert Line Level to Mic Level - Electrical Engineering Stack Exchange