Well, when I saw the title of this thread I jumped for joy. One of my jumpers (that's a jumper as in sweater, something to keep one's upper body warm during these cold winter months and not one who jumps, be it long ways, high ways, byways, through hoops - as Andyson does to play WGT, for joy, or any other kind of jump) needs a new sleeve and I thought "Yes, found one!". Imagine my huge disappointment when it was not a jumper sleeve at all, but a 'box' of balls.
So my search goes on to find a new sleeve for my one-sleeved jumper.