I have I-pad model: A2152 and A2270. Which apple pen can be used on both? Is it fist generation only?

Hello. It looks like you have an iPad Air 3rd generation and an iPad 8th generation. Both of these models are compatible with the Apple Pencil 1st generation. For specific details regarding compatibility between iPad and Apple Pencil models, please see this article.

The model numbers identify an iPad Air3 (A2152) and an iPad8 (A2270).

Your Air3 is compatible with the second generation Apple Pencil - whilst your iPad8 supports the first generation Pencil.

The Pencils are not interchangeable - as the first and second generation Pencil use an entirely different pairing and charging interface. The second generation Pencil can only be used with iPad models that have the magnetic/inductive dock that is exclusively designed for the Pencil. By contrast, the first generation Pencil can only be used with compatible models of iPad that feature a Lightning connector.

Here is the definitive compatibility list for Apple Pencil and iPad:

Apple Pencil (2nd generation)

You can use Apple Pencil (2nd generation) with these iPad models: 

• iPad mini (6th generation)
• iPad Air (4th generation)
• iPad Pro 12.9-inch (3rd generation) and later
• iPad Pro 11-inch (1st generation) and later

Apple Pencil (1st generation)

You can use Apple Pencil (1st generation) with these iPad models:

• iPad (9th generation)
• iPad (8th generation)
• iPad mini (5th generation)
• iPad (7th generation)
• iPad (6th generation)
• iPad Air (3rd generation)
• iPad Pro 12.9-inch (1st or 2nd generation)
• iPad Pro 10.5-inch
• iPad Pro 9.7-inch

Not sure which iPad you have? Identify your iPad model.

Hello. It looks like the iPad Air 3rd generation is only compatible with the 1st generation Apple Pencil. Unless I am mistaken.