What sensor is missing?

[JohnVteC]

Am looking to found out what sensor is missing and if its good to have it or not!! anyone knows what sensor missing from here?

 

[JohnVteC]

its a Honda Civic Ek3 1996 model B series Swap

 

[b16 mini]

Most likely for the outside air temp sensor that some models have,
Or your horn?

 

[JohnVteC]

Most likely for the outside air temp sensor that some models have,
Or your horn?

i have horn ready on that one is missing and i can't find what it is .. they told me maybe its a sensor that measures the outside temp for the a/c or i don't know