... No.4522002210,9522002210 4522002110 Cast iron / aluminium Trailer Air brake coupling head for full trailer, tractor (1).Material: ... in it,to reinforce the safety of the air brake system,it is easy to use and fix ... .(3).Use to connect the air brake system of the heavy truck,semi-trailer,full ... with me and visit our company ! trailer brake coupling pamp coupling,air brake system ,brake valve