Nancy's Knit Knacks Heavy Duty Ball WinderMade of Maple hardwood, 10mm and 3 8" diameter steel shafts, and commercial grade, heavy duty Swiss gears. Ball Winder includes 2 heavy duty table clamps (5 16" diameter L bolts). These allow for mounting to table thicknesses of up to 2. 5". Our clamping systems are preferred by most fiber artists. 1 year limited warranty for both consumer and commercial use. Designed and manufactured in the USA with old fashioned engineering expertise and quality