Q: What size tube do I use for the 18X5X5 tire on a 337 Skymaster?
Use part # 06-01221, LEAKGUARD INNER TUBE 18-5.5, for the 18x5x5 tire.
Q: What size tube is needed for the 15x6.00-6 tires for the Cardinal RG?
This tube, Part# 06-05305, will work great.
Q: What is the difference between a 6.00x6 tire and a 15/6.00x6?
The first number before the "x" indicates the tire's height or diameter when inflated and not under load. The middle number, that is the digits between the "x" and the "-," indicates the tire's width. So, the 15 x 600-6 specifically calls out the height as 15 inches. The standard 600-6 will be taller.