How is the Get method used with DynamicParameters?

I am trying to run a test to see if I loaded a DynamicParameters object correctly. However, I cannot figure out what the Type is that I should use. I get exceptions when I try to use C#/.NET types (int, string, etc.). I tried to use SqlDbType, but that didn't work. I looked at source and I see that the value is stored as a IDbDataParameter and then cast to the type. Obviously, the types I'm trying don't cast. The data I'm testing with are int. How can I get the values?

var dbParams = new DynamicParameters();
dbParams.Add( "Field1", 1 );
var value = dbParams.Get<int>( "Field1" ); // throws an exception