This is s mechanical 12x18x6 single tank releaser. It is rated for 500 taps but I ran it on 600. This was not an issue but she did cycle fast when sap was running hard. This is set up with two 1' inputs but can manage four. Vacuum gauge on tank is handy.
This unit was a real workhorse for us.
It is very similar to:
https://bascommaple.com/products/vrvs?_pos=50&_sid=682f0da93&_ss=r
The price is fair and cash only. If the ad is up, the unit is available.