Umbrella Swifts are made from birch, in two sizes, the regular size which holds skeins up to 72 inch around, and the large swift which holds skeins up to 100 inch around. They are constructed and finished to get the most appropriate surface for the yarn. These are the original Swedish made swifts and not an imitation. Look for Sweden on the logo. You can clamp these swifts to stand vertically, as shown. Or you can mount them horizontally which can make for easier un-winding. Use the swift in conjunction with the ball winder.