Red Top or Black Top Air Jet

The air jet valve is located inside the water reservoir and is screwed into the side of the safety valve holder block. Just look for the small hand grenade style ring on the side of the block

You will need a 10mm wrench to remove the valve. Simply unscrew the valve by turning it counterclockwise

Once removed, use a ruler, a tape measure, or calipers and measure across the bottom of the end with the threads

If it measures 0.375 (3/8) inch, it is a Black Top. If it measures 0.25 (1/4) inch, it is a Red Top

The description for the Black Top Air Jet Valve is kind of counterintuitive. It reads 1/8-28 BSP thread. At first glance, you just notice the 1/8 and presume that means it is 1/8" in diameter. Wrong. I have to admit, I made this mistake myself.

The 1/8 is designating the thread size, not the diameter and the 28 indicates the "thread pitch" (or angle), and the BSP means "British Standard Pipe"

Once you have determined which air jet valve you need, simply go to the parts listing and find the part that fits you unit