Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_19901_1 (trigger_pack VARCHAR, rear_sight_type VARCHAR, colt_model_no VARCHAR)

### Question ###
What is the trigger pack on the Colt 602 with the a1 rear sight type? 

### Accurate SQL ###

SELECT trigger_pack FROM table_19901_1 WHERE rear_sight_type = "A1" AND colt_model_no = "602"