Traditional Culture Encyclopedia - Photography major - What is 250 marks?

What is 250 marks?

1 and DM-250 are depth meters, which are Japanese TECLOCK DM-2 10 depth meters.

2. It is a model of photographic equipment, Kimbe DM-250 photographic lamp, DM-250 digital master SLR camera and lens.

3. It is a sharpener, model: DM-250 sharpener.

..... and so on.