Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
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? 
### Answer:
SELECT trigger_pack FROM table_19901_1 WHERE rear_sight_type = "A1" AND colt_model_no = "602"