SIZE: -16B 5 or 8 inch diameter ball bearing roller. MATERIAL: Housing be made of carbon steel material. FEATURES: 360 degree universal transfer bearing. CAPACITY: With a load bearing capacity of 33.07 lbs. NOTE: Two screw holes in each bearing,screws are not included here. 1.Ball Transfer Unit are omni-directional load-bearing spherical balls mounted inside a restraining fixture. 2.360 universal transfer bearings is suitable for curved work created on band saws and router tables. Product Name: Ball Transfer Unit Color: Silver Tone Weight: 520g Model: -16B Capacity(Max.): 15kg or 33.07lb Ball Diameter: 5 or 8-inch Dimension: 45 x 19mm or 1.8-inch x 0.75-inch(Max.D x H) Mount Hole Dia.: 4mm or 0.16-inch Mount Hole Distance: 30mm or 1.2-inch Package Content: 12pcs x Ball Transfer Unit Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.