NLM is the default format used by some models of Nokia phones for saving logo files. NLMs can contain all types of images that can be used for customizing phone imagery. Opening NLM files outside Nokia devices is probably difficult and requires conversion.
The quick and simple way to handle your files is to get a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch conversions. As you will soon realize, reaConverter will help you avoid spending countless hours trying to figure out how to convert multiple NLM files as once.
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