Different make it possible to meet different work requirements. The ergonomic design makes it very comfortable to hold and non-slip.Exquisite and professional workmanship makes it very sturdy and durable. And the wide range of applications makes it very practical and useful.Made of high speed steel material, it is very durable to use.There are four (5-7mm, 8-11mm, 10-15mm, 12-19mm) in this set.It can be used in living room, kitchen, bathroom, balcony, etc. all kinds of environments beautiful seam, simple and convenient.Item Name: Pressure Seam Steel BallMaterial: High Speed SteelQuantity: 4PcsFeatures: Double Head, Easy to Operate, SturdySize Details: 5-7mm: 11.5cm x 0.7cm x 0.7cm or 4.53" x 0.28" x 0.28" (Approx.)8-11mm: 12cm x 1.1cm x 1.1cm or 4.72" x 0.43" x 0.43" (Approx.)10-15mm: 12.8cm x 1.5cm x 1.5cm or 5.04" x 0.59" x 0.59" (Approx.)12-19mm: 13cm x 1.9cm x 1.9cm or 5.12" x 0.75" x 0.75" (Approx.)Notes:Due to the light and screen setting difference, the item's color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:4 x Pressure Seam Steel Balls (5-7mm, 8-11mm, 10-15mm, 12-19mm) Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.