As resell rights cannot be passed on by anyone other than me and I have chosen to do so exclusively on Fiverr, it should be some time before the collection reaches anything like the internet saturation level typical of many of the old reseller Twitter header packs doing the rounds, so you can be confident that you are offering your buyers or subscribers something a bit different in an up-to-date size. Of course, there's nothing to stop you from just using the headers yourself!
[No] Can be given away free
30 Resell Rights Twitter Headers
30 Twitter headers (2016 dimensions) with resell rights