rail
1: 4 inch GT100 100 single top wire
2: 5 inch GT125 150 (single top wire)
3: 6 inch GT150 200 (double top wire)
4: 6 inch GT150 300 (double top wire)
5: 6 inch GT150 400 (double top wire)
6: 7 inch GT175 200 (double top wire)
7: 7 inch GT175 300 (double top wire)
8: 7 inch GT175 400 (double top wire)