4(1)-IN-1(4)-OUT 3.5mm AUX audio selector designed for customers having several audio sources and outputs, simple to use, plug and play, no power supply required | 4 in 1 out: Support up to 4 audio source inputs and select 1 audio source output | 1 in 4 out: 1 audio source input,and 4 ports output can be switch to amp or active speakers or headphone (If you need 2 or 3 ports output to play at the same time, you need to press 2 or 3 buttons at the same time and keep them locked.) | This is a good idea to solve the problem of unplugging and plugging the wire | Build in solid aluminium CNC chassis, looks nice and durable

2(1)-IN-1(2)-OUT RCA audio selector designed for customers having several audio sources and outputs, simple to use, plug and play, no power supply required | RCA audio switch, support volume control; one key to mute; small size, easy to place, suitable for your desktop and office | Select audio input between 1 and 2 with 1/2 switcher and get one output | Select audio output between 1 and 2 to receive one input | This is a good idea to solve the problem of unplugging and plugging the wire

This compact switcher box allows connection of up to three stereo sources, between two amplifiers，3 in 2 out or 2 in 3 out | The most feature: Design as indepently ground connection. Switching signal source is switching ground connection.(ie., all sources are not common GND.) | Stereo Switch Box with Signal Lossless, Sturdy Aluminum case Strong Anti-Interference, Compact Connector Distributor RCA L/R Stereo Splitter Boxes. | Build in quality aluminum chassis, looks nice and durable | This is a passive non-powered device. Plug and play

CONTROL 2 SPEAKERS: multichannel speaker switcher controls up to 2 pairs of speakers that connected to a stereo amplifier at the same time or in combination | The Multi-Zone A B Speaker Selector Switch is perfect for your home theater sound system w/ 80W max power per channel. For use w/ 8-16ohm impedance speakers | Two switches are installed in parallel to control two sets of speakers | Accept up to 14AWG speaker wire and No extra power supply needed. | Metal housing with a compact slim tabletop design that complements any home theater setup

A21 is an amp switcher/speaker switcher. You can choose 2-IN-1-OUT for 2 amplifiers to 1 pair of speakers, or in reversible direction of 1-IN-2-OUT for 1 amplifier to 2 pairs of speakers. So you could compare 2 amps or 2 pairs of zone speakers quickly and conveniently | The Multi-Zone A B Speaker Selector Switch is perfect for your home theater sound system w/ 80W max power per channel. For use w/ 8-16 ohm impedance speakers | It is a good idea to solve the problem of unplugging and plugging the speaker wires. | Small size, in solid aluminum chassis, looks nice and durable | Accept up to 14AWG speaker wire,Terminals blocks use conveniently, easy to set up. Passive design, no need pwer supply