Super bright replacement bulb, pre-tested. Each card contains 2 bulbs. No. BK02GS: 2 "D", 2.40V/.70A No. BK03GS: 3 "D", 3.60V/.75A No. BK04GS: 2 "AA" and 2 "C", 2.20V/ No. BK13GS: 6V, 4 "AA", 4 "AAA", 4 "C", and 4 "D", 4.80V/.75A