The Shimano CS-HG201 is the suitable 9-speed cassette for ALTUS M2000 group.
Product features – Shimano ALTUS CS-HG201-9

Use: MTB/Trekking
Group: ALTUS M2000
Model: CS-HG201-9
Type: HG
Gear: 9-speed
Compatible chain: HG 9-speed

Gradation (choose variant)

11-32 (11-13-15-17-19-21-24-28-32 teeth)
11-34 (11-13-15-17-20-23-26-30-34 teeth)
11-36 (11-13-15-17-20-23-26-30-36 teeth)

Material

Spockets: Steel
Lock ring: Steel

Color

silver (nickel plated)