WML2508ZZX Miniature Shielded Bearing 2.5mm x 8mm x 4mmWML2508ZZX Ball Bearing 2. 5 x 8 x 4 WML2508ZZX High Quality bearing, this is a go to bearing size that fits lots of RC cars and trucks, or any application that uses this size 2. 5mm x 8mm x 4mm. made from durable 52100 alloy steel, commonly known as chrome steel and can rotate up to 85000 rpm, each Comes with double metal shields (ZZ) to keep out dust and dirt, plus its pre lubricated with grease so its ready to roll right away. WML2508ZZX Size: 2.