This a double trigger depend valve is made by CG ConnElkhart.1956. Model 72h with the E plug valve making it double trigger.this horn also can be use as single trigger by removing the E plug valve.l have the F slide also  the is included the horn is very good condition for the vintage.the slide is also original no lock on slide typical of the time 1956 . The bell 9 1/2 inches.yellow brass