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3.5mm Stereo Male to 3.5mm Mono Female Adapter (TAA Compliant) | Audio Adapters and Couplers | Adapters and Couplers | Audio Video
Switchcraft AudioStix Stereo 3.5mm Female to Balanced Mono 318
Kentek RCA mono male to RCA RW female M/F Y adapter converter connector for audio stereo TV system - Walmart.com
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Amazon.com: 3.5mm Stereo Male to Dual 3.5mm Mono Male Audio Cable, 1ft 3.5mm 1/8" TRS Male to 2 x 3.5mm 1/8" TS Male Y Breakout Cable Splitter Adapter for Headphone, Speaker :
Monoprice 3.5mm TS Mono Plug to 3.5mm TRS Stereo Jack Adapter, Gold Plated - Walmart.com
Stereo to mono converter cable, 50cm
1/4" Stereo Audio Jack Plug Adapter Single Male To Female 6.35mm Dual Mono Stereo Jack Headphone Microphone Y Splitter Converter - Audio & Video Cables - AliExpress