This is the Arrma ARA610038 Ball Bearing 15x21x4mm 2RS (2pcs)

Overview
These high-quality Rubber Shielded Ball Bearings make an ideal replacement part for your ARRMA vehicle.

Features
Premium ball-raced bearings for ultra-smooth operation in all conditions
Precision manufactured for fast and easy fit and consistent servicing
Manufactured to consistent tolerance for safe and secure assembly
High-quality rubber shields for enhanced protection against the elements
Keeping dirt, water, and dust out, and lubrication in, means more time bashing and less time wrenching

Specifications
Inside diameter: 15mm
Outside diameter: 21mm
Thickness: 4mm

Included items
Ball Bearing 15x21x4mm 2Pcs