There have been two versions of the Ultra LT and I believe they were/are both Walmart exclusives. As with all Roku models, it's the model number that's the important thing. The 4662 came out in 2019 and seemed to me to be a stripped down 4670. The 4801 is virtually identical to the 4800/4802. Again, it's stripped down with no USB port. The wiki gives pretty good information, although it's inaccurate when it comes to the 4802 which is not an LT and does have a USB port.
I don't think I'd get a 4662, but a 4801 wouldn't be any different than the current Ultra (4802) except for the lack of a USB port and maybe the remote. I don't know if the LT comes with a Voice Remote Pro (rechargeable), but given that Walmart does whatever it takes to knock off a few bucks it probably doesn't.
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