Slide rail assembly

A slide rail assembly, comprising:

• a first rail comprising an upper wall, a lower wall, and a sidewall connected between the upper wall and the lower wall;
• a second rail displaceable with respect to the first rail;
• a ball bearing assembly movably mounted between the first rail and the second rail, wherein the ball bearing assembly includes a ball retainer and a plurality of balls;
• the ball retainer includes an upper retainer portion, a lower retainer portion, and a side portion connected between the upper retainer portion and the lower retainer portion;
• the upper retainer portion is adjacent to the upper wall of the first rail;
• the lower retainer portion is adjacent to the lower wall of the first rail;
• the side portion is adjacent to the sidewall of the first rail;
• the balls are mounted in the upper retainer portion and the lower retainer portion of the ball retainer;
• and the ball retainer includes a stopping feature;
• and
• a damping device corresponding to the stopping feature of the ball retainer;
• wherein when the second rail is displaced, and thereby extended, with respect to the first rail, the ball retainer is driven to displace by the second rail, and when the stopping feature of the ball retainer comes into contact with the damping device, a damping effect is produced.