gts Bakelite Container

Original German bakelite container marked gts on the lid. There is an M marking on the bottom. Overall good condition. Some bubbling in the Bakelite. This is a military container of some type. I feel like I used to know what it was for, but its now escaping me. Oh no, its starting - all the basically useless information I have amassed over my many years is starting to slip away and this, this container is where it all began.