How does the unit itself recharge?
It has a micro USB charging cable in the box according to the specs, so I’m guessing it uses that.
(Please note: I don’t work for Woot, I just volunteer to help out here on the forums.)
I would agree with that assessment since it also says the wall adapter is sold separately. 
It’s funny what you learn when you read these things, huh?
Not everyone realizes there is a specs tab. I think we’ve all been guilty of overlooking things. It happens.
I suppose. And we should suppose that some people have never charged a portable battery before too…
I just think it’s just better to err on the side of kindness. 
Totally agree.
Bought one because the USB port on my phone is acting up, but the wireless charging still works fine. But after fulling charging this pack it will not charge wireless. The USB ports work fine, but the wireless charging does not work at all. Tried three different phones (all Samsung). Tried removing cover, made sure phone was in place at power on, tried different positions, different orientations, nothing works. Looking into return/warranty, but the warranty linked form the item description implies that they will not honor it for purchases from woot: Warranty – Aduro Products
" Our policy is to honor product warranties and/or perform services only on products purchased from an authorized Aduro seller and only accompanied by a receipt or proof of purchase. If you purchase an Aduro product from an unauthorized seller, your Aduro warranty will not be valid."
EDIT: I should have known not to worry. WOOT took care of me and I got a refund. Not excited about the product, but as always a great experience at WOOT!
We are an authorized seller of Aduro products.
Does this work / charge the Samsung Galaxy S21 Ultra 5G??
Does your phone have QI charging? Then yes.
Does your phone have a place to plug in a cable and accept a 5V/2.1amp flow? Then yes.
(Please Note: I’m not employed by Woot, but I volunteer to help in the forums.)