Purchased three different brands for testing and eventua lpurchase of an additional 8 units of the brand we felt was best for our needs. This had to happen in 30 days, from testing to final install of the 8 additional units. Don't expect expedited delivery service even if you pay for express delivery. This seller is not to be trusted with delivery promises. Paid for UPS express shipping and expected it in no more than 8 days... just like every other UPS express delivery for CN. Original UPS label "created" Feb 11. Then a new UPS label/tracking number was generated Feb 27. Almost one month later, and many excuses, the item was delivered on March 7... you know, about 8 days, sort of like how long it should take for UPS express to deliver out of CN. Obviously, sample unit arrived way too late for testing purposes. If you want your items in a reasonable amount of time, these are not the sellers you are looking for. Very terrible. Finally had a chance to test the unit. Keeps crashing