channel 11 discharges through outlet stubs 13 and 14 the recoil or thrust forces thereby generated cancel each other in the example embodiment illustrated in fig3 the insert defining the outlet cross section 17 of the first outlet stub 13 or second outlet stub 14 respectively consists of a three armed baffle body 18 which is inserted and fixed into the connecting area 12 of the t shaped connecting piece 10 in such a manner that the baffle body results in differently sized outlet cross sections required to inflate the differently sized airbag region volumes the baffle body 18 again consists of a non heat resistant material in this specification and claims the phrase u201c differently sized outlet cross sections u201d includes an outlet stub or stubs in which a baffle or deflector device e g baffle body 18 is installed such that unequal volumes of gas are discharged from the first and second outlet stubs in the example embodiments illustrated in fig4 and 5 the insert that adjusts the cross section of outlet stubs 13 and 14 consists of a bolt 19 which from the outside of the t shaped connecting piece 10 is inserted or screwed into the associated outlet stub 13 engaging the walls in the latter case the section 20 of the bolt 19 lying in the cross section 20 or cavity of the associated outlet stub 13 consists of a non heat resistant material whereas the section 21.