Our Big Boys™ Truck Nutz are molded out of a Poly-pro-py-lene Co-poly-mer. This tough material makes these balls as hard as a rock AND tough all the way through. Road Rash is part of life, and these nuts show their colors throughout when abused. These Truck Nutz are : 7-5/8" long, 4-1/4" wide, 1-7/8" thick - Weight 10.3 oz's - Hole 3/8"