This is an excellent example of the famous Watermans Ideal. This is the 52 1/2 V in Black Hard Rubber. The pen was made in the USA around 1925 and is in very good condition with a good imprint. The 52 1/2V is the shorter version of the standard 52, the V stands for Vest Pocket so the pen was designed to be held in the pocket without being visible to comply with military regulations at the time. Despite being short the pen is very usable and when the cap is posted on the end of the barrel it is well balanced.
The pen has been fully restored and now works perfectly. It is a lever filler and is fitted with an amazing Extra Fine Semi flex nib.