This is the Essentials* bearing kit by Avid RC for the Xray X4.
*The Essentials kit removes the bearings that don't typically need replacing such as the (4) 5x8 bellcranks, (4) 3x6 sway bars, and (2) 3x8 belt tensioner bearings. You can always make a custom kit by shopping for the bearings individually but the Essentials kit quickly saves you money.
X4 | Essentials