The ’ M ’ means the wire ties come in a bundle of 1000. Another ending is ’ C ’ which means a bundle of 100. The ’ 0 ’ means the color black, while no 0 means it is natural nylon color.
There is a customer who asked the similar question about ABM100-AT-D0. The meaning of suffix 0
The 0 indicates that the part will be the color black.
Go under the Material and Color Chart and this goes for all Panduit product. 0 = Weather Resistant Nylon 6.6, color black.