Sescom SES-3MIX Corded Electric 3-Input / 1-Output Passive XLR Mixer - Black

Since the SES-3MIX utilizes a passive design that doesn't require power, it needs no batteries or power adapter. As a result, it is optimal for mixing line-level signals or microphones that don't need phantom power, but it should not be used with high-impedance sources such as electric guitars.

eBay