This is a lovely example of an early safety pen made by Whytwarth of England. Safety pens have a retracting nib which is activated by turning the knob at the end of the pen, when the nib is extended it forms a seal on the inside of the barrel to prevent leaks. It is a simple concept but the pens worked well and were very popular.
This is one of the larger pens made from Black Hard Rubber with a chased pattern. The manufacturers markings have long ago worn off and the pen has discoloured slightly where it has been exposed to light.
The huge Warranted nib is 14ct gold and writes with a medium line with a lovely flex to it.
These early safety pens are very collectable and this one, although plain Black Rubber is a great example.