Auto air vent

I'm preparing to install a Laing SM 303 re circulation pump in my house. It requires a return line from the furthest away outlet. This is not a problem, but in that line I have to install a couple of cut off valves, a swing check valve, a hose bib, and an automatic air vent. No questions about any of the components mentioned except the auto air vent. I know what it is supposed to do, but where do I find one and what am I looking for specifically? My web searches have produced a number of vents, but some are only for heating systems, some specify non potable water, and I am a little confused by all of the choices. I'm sure you plumbers are acquainted with these devices. I'd appreciate a make and model of the appliance I should ask for.

Laing makes an install kit for the sm303. It includes all the components you need, except the hose bibb and assorted copper fittings. The air vent is an automatic valve which bleeds any air which might be in the system. Air is bad and can damage this type of pump.

Thanks

OK then. I'll go to my local plumbing supply house and get the kit as you describe. I have all of the assorted fittings I'll need, I just need to pickup some pipe, the vent, and check valve and I'm good to go. Thanks for the info.