Should be 1/2" . I got some in a bag'o rope. Splices OK. Go to tuefelberger website for splicing instructions. They also have photos of the different sizes/colors.
I think maybe when TS had the 'bag of rope' on sale they couldn't keep up with demand. It's like decent linear footage was lopped off a reel. I got 15-20' of that 3/4'' tuefelberger and some nice hanks of others. there's quite a bit hanging in my basement.