Vane operated tail fuzes of this type incorporate an antiwithdrawal device and are designed for special application. The fuzes act to detonate the bomb after a delay of from 1 to 144 hours; specifically, 1, 2, 6, 12, 24, 36, 72 or 144 hours. Less than 100 feet of air travel is necessary to initiate the delay action. Any attempt to unscrew these fuzes will result in the functioning of the antiwithdrawal mechanism, followed by instantaneous detonation. Tail fuzes M123A1, M124A1 and M125A1 differ in overall length so that the same type fuze can be used in various size bombs. The differences in length are necessary to locate the arming vanes properly in the airstream. Each fuze of the series has a nominal delay-firing time indicated on the fuze. This type of fuze is particularly responsive to changes in temperature. Temperatures above 50° F. accelerate its action while temperatures below 50° F. retard it.