They are highly flexible and yet more rugged than basic vinyl sleeves. They have been designed with lines near the center crease line to help minimize the wear and tear of regular use. Don't get me wrong, like anything made of vinyl, they will break down, but you can't go wrong for the price.
Does NOT ship with Tracking. I'm a US-based seller, and this will be mailed out via mail without a ($3.00) tracking number. Letter mail is typically a 5-7 business day service. Don’t let the lack of a tracking number worry you; occasionally, mail pieces go missing, and when they do, I replace them. (missing mail happens with trackable pieces, too…we’ve all experienced a package scanned delivered but never received it…..it’s almost more annoying)