Retractable sword
Alternate reality
Hikaru Sulu activating his sword
The expanded sword
A retractable sword was a hand-held weapon, with a blade that could be retracted by pressing a button on the hilt. When sheathed, the blade was entirely contained within the hilt, making it small, compact and easy to carry. When released, the blade extended rapidly to a length of approximately one meter by unfolding in segments.
Hikaru Sulu owned a retractable sword and used it on the Narada's drill platform above Vulcan in 2258, to fight off a pair of Romulans. (Star Trek)