1----Good Load-bearing Capacity: The self adhesive caster wheels is made of high-quality ABS and stainless steel, strong and wear-resistant with a maximum load of 20 pounds. Four rollers together provide a maximum load capacity of 80 pounds. 2----Self-Adhesive Mini Casters: Made of Strong Eco-friendly ABS materials and 304 stainless steel ball transfers, it will has a long-term service life, sturdy and durable. 3----360 Free Rotation: These 360-degree rotation ball type adhesive caster will move smoothly in all directions without making noise or scratches/marks on the floor. 4----Wide Applications: These mini casters can be applied to shoes box, trash bin, small container for easier moving, also a nice DIY accessories for kids toy, art craft works and more. 5----Easy to Use: 2 ways of mounting for transmission Self-Adhesive Casters. You can simply peel the adhesives on the back, firmly press the caster onto the smooth surface or fix it on the bottom with screws according to the item type. Highlights: --- It can slide to all direction you want, and move the heavy box easily. --- Made of sturdy ABS material and small steel balls with a maximum load of 8 kg. --- The silent mini caster is stable and quiet, not easy to shake and scratch the ground. --- Place the caster on the bottom of the box for 24 hours to use it, no complicated process. --- Effective labor saving swivel caster can be applied to toy box, trash bin, small container for easier moving Features: Material: ABS+stainless steel Product size: Single ball: 4.5*2.8cm, hole spacing 3.5cm/Single ball four-pack with 15kg load capacity Double ball: 5.3*2.9cm, hole spacing 4.5cm/Double ball four-pack load 25kg Diameter of steel ball: 10mm Colour: black, white