How can advertisers specify targeting for mobile devices in Twitter Ads?

In Twitter Ads, advertisers can specify targeting for mobile devices in the following ways:

1. **Device Type**: Advertisers can target users who are accessing Twitter on a mobile device, such as a smartphone or tablet. This can be done by selecting "Mobile" in the "Device" section of the audience targeting options.

2. **Operating System**: Advertisers can target users who are accessing Twitter on a specific mobile operating system, such as iOS (Apple) or Android (Google). This can be done by selecting the desired operating system(s) in the "Operating System" section of the audience targeting options.

3. **Carrier**: Advertisers can target users who are accessing Twitter on a specific mobile carrier, such as AT&T, Verizon, or T-Mobile. This can be done by selecting the desired carrier(s) in the "Carrier" section of the audience targeting options.

4. **Mobile Connection Type**: Advertisers can target users who are accessing Twitter on a specific type of mobile connection, such as 4G, 3G, or Wi-Fi. This can be done by selecting the desired connection type(s) in the "Connection" section of the audience targeting options.

5. **Mobile App or Mobile Web**: Advertisers can target users who are accessing Twitter through the Twitter app or through a mobile web browser. This can be done by selecting the desired option in the "Platform" section of the audience targeting options.

6. **Device Model**: Advertisers can target users who are accessing Twitter on a specific model of mobile device, such as the iPhone 12 or Samsung Galaxy S21. This can be done by selecting the desired device model(s) in the "Device Model" section of the audience targeting options.

Remember, the effectiveness of these targeting options will depend on your specific audience and advertising goals. It's important to regularly review and analyze your ad performance metrics to ensure your targeting strategies are effective.