This yarn ball winder (Model YBW-A) makes center pull yarn balls with a capacity of about 4 oz. The clamp-on base allows it to be firmly fixed at the edges of tables, chairs, benches, or any other convenient locations. The maximum thickness of table that this can clamp on to is about 1 3/4". It is best to be used with a swift yarn winder (Umbrella or Amish style, both available under Stanwood Needlecraft brand names). But you can easily replace a swift with other devices or just simply your arms. The craftsmanship on these ball winders is superior. In comparison to our model YBW-B, this winder is smoother and makes less noise while winding.