For sale is a dual-channel wireless microphone system from Audio-Technica.
It includes a handheld microphone and belt pack with lavalier and headset microphones.
This isn't a single-channel, combo kit, where you can't have both on at the same time.
It includes the power supply, a lav/headset case, and upgraded antennae.
The transmitters use AA batteries, which is much more convenient (and cheaper) than the 9V batteries that many other transmitters use.
The belt pack uses AT's HiRose 4-pin connector, should you want to purchase an additional microphone.

B&H currently sells this kit (without the extra headset mic) for $950.

I've had multiple years of good service, from this system.
I'm wanting to upgrade to a higher-level wireless system, like the Shure SLX-D or ULX-D ($3000-$6000).
As such, I want to help subsidize the cost.

The System 10 Pro system runs on the 2.4Ghz frequency range.
That is nice if UHF/VHF frequency bands are heavily-congested and creating interference.
It does run on the same spectrum that Bluetooth and Wi-Fi occupy.
You may get interference or dropouts if there is a lot of activity, in that band, but it does have the ability to jump to other frequencies.

A novel feature of the System 10 Pro series is the ability for the antenna modules to disconnect from the main chassis and be mounted in a more favorable position.
The two modules connect with a standard network cable.
You can even cascade multiple System 10 Pro units together.
With a half-rack design, you can mount two systems in 1u of rack space.
That's four channels of wireless microphones in 1u of rack space.
Unfortunately, I don't think I still have the rack hardware.
If I happen to find them, I will include them with the purchase.