Just saw this and bought a few. Sale ends in 5 hrs 57 mins.
FWIW, this may be a rolling “sale” where there’s always time left. You posted this 14 hours ago with less than six hours left, but I’m looking at the site now and see there’s supposedly 5:40 left along with the typical “stock is low, order now” malarkey. I bought a welder last fall the day after Thanksgiving because of a similar “limited time” sale, and now at the end of March it’s still going on – they change the holiday periodically, but the “sale” has been going perpetually for months (at least). I suspect it’s the same thing here. Devices look interesting but perhaps not something people need to make a “now or never” rush decision about buying. 
Update 28 hours after my original post above: Still 50% off, but now they’ve removed the countdown. Guess the stock isn’t as low and the time isn’t as limited as they’d like us to believe. 
Yup… I just went to the page for the first time… Only 5 hours and 40 minutes left!