2b second mounting facility thread class 4.220" overall length 3.250" overall width release time is variable, controlled pneumatically by a calibrated dial unc second mounting facility thread series
2a single mounting facility thread class right-hand single mounting facility 1.390" overall length 0.734" overall width 48 single mounting facility thread quantity per inch unc single mounting facility thread series
Used on chassis, truck (tss). (ac-130a, ac-130h, mc-130h, ec-130e, hc-130) a. 2a thread class 1.688" overall length 1.500" overall width 32 thread quantity per inch weapon system essential unc thread series