CS4 1H- 16 free floating trap is a China model modified from Japanese TLV J series trap. J series steam traps are the body band, J5, J7,,,, and later the products were changed to J3N, J5N, J7N,,,, so I think' n' may be added for this reason, but it is obviously wrong to use' CS 4 1H- 16N' because it shows that the valve body material is nylon.