The 50 wt spools are distinguished by orange holders. To release the thread twist off the end cap, when you have finished you can tuck in the thread ends and twist the end cap back on. Neat way to tidy up those flapping and tangling loose ends!
You will love this thread for hand piecing and appliqué. Because it is lightweight but strong it makes a thinner seam. Thinner seams - less bulk in your quilt. And there are squillions of colours so you can match the thread to your fabric.