Based on this product's specifications, here are some alternatives and similar models
Polax replacement roller multicolor 6x30x100 mm for paint rollers
Summary description:
Replacement roller by Polax, multicolor design, dimensions 6 x 30 x 100 mm. Intended as a spare sleeve for compatible paint rollers or small application tools. Useful for touch-ups, small surface painting and craft projects where a compact roller head is required. Easy to fit on standard 6 mm shafts and suitable for quick on-site replacement.