Auvio portable headphone amp for $20 {limit 5}

If you like to explore or experiment upon or compare budget portable headphone amps, the Auvio headphone amp (it doesn’t appear to have a model name) is currently on sale for $20 with a limit of five per customer by a marketplace seller wit the order fulfilled by Amazon so it is eligible for free 2-day shipping. It averages 4 out of 5 based on 17 customer reviews