Collection: Vivo X90 / X100 / X100 Pro & Vivo X200 /200T/ X200 Pro Accessories

1. Compatibility: Ensure that the case is specifically designed for the Vivo X100 or X100 Pro. This will ensure that buttons, ports, and camera openings align correctly.

2. Filter Attachment: Look for cases that feature a built-in lens mount or thread to attach filters such as ND (Neutral Density) or polarizing filters. This could enhance photography capabilities significantly.

3. Material and Protection: Consider the material of the case (silicone, hard plastic, etc.) for durability and grip. A case that offers good drop protection is also essential.

4. Weight and Bulk: Since you are looking for functionality with attachable filters, find a case that doesn’t add too much bulk to the phone for better portability.

5. Brand Reviews: Check for trustworthy brands that produce camera accessories. Reviews and ratings from other users can provide insights into the practicality and reliability of the case.

If you're seeking a specific model or retailer, websites like Amazon, eBay, or dedicated mobile accessory sites might have options for filter attachable cases for the Vivo X100 and X100 Pro. Always read product descriptions and customer reviews to ensure that the case meets your requirements.