It is a very common pencil here in Singapore and i remember using them when i was below the age of ten. Then of course mechanical pencils became common, and i started using those instead.
You can find them in Popular book shops where they go for $2.85 for a double pack of a dozen (24 pencils).
What i like about them is the exterior paint work and design. The lead is good and dark, but it is soft and does not hold a point particularly well. The wood is some generic kind, with no smell but it sharpens well.
Overall a good pencil to use, without concerns for its preciousness, but yet good enough to like, and easily available so one can continue to use it.
I have been trying to find information on the different uses of different camera filters for ages. Before the advent of digital cameras, filters were he means by which one could influence the look and colour of the image, and it had to be done before the shot.
Below is the Tiffen information pamphlet that was in the filter box that i received from an Ebay find. I hope you find it a handy reference for your own explorations.