Final answer:
The M734A1 fuze series contains a rain-insensitive screen to allow firing through heavy rainstorms without premature functioning of the ammunition.
Step-by-step explanation:
The M734A1 fuze is designed to be used with a 155mm artillery round and is capable of functioning properly even when fired through a heavy rainstorm. The rain-insensitive screen on the M734A1 fuze prevents moisture from interfering with the fuze's sensitive components, ensuring that the round of ammunition functions correctly.