This is a basic gray putty that fills well and stays in place. This dries fast, and any excess can be easily cut away with a hobby knife. It sands pretty well, but only if it has dried. If you try to sand it before it dries completely it will make a mess. This should be used with putty application tools to get the best results. A tube of this is not small, and should last through many models.

I've tried both the Tamiya and the Testors putty and personally I find the Testor's one to be better. This putty dries really quickly on the outside, so if you don't move fast enough the outside of the putty dries and hardens while the inside is still soft and liquid-like. This makes it messier and harder to apply, in my opinion. The Testor's one dries uniformly and is easier to work with in my experience.

Great all around filler. Dries fast and sands easily. Only complaint is that it will shrink when filling larger areas so two coats may be necessary. But all in all good stuff. One tube last forever.