Keeve Trennis' lightsaber was a split saber composed of two identical green lightsabers that could combine to form a single Double-bladed lightsaber. Trennis used her lightsaber as either one double-bladed weapon or two single-bladed ones depending on how she preferred to fight.
Constructed sometime during her Jedi training, Keeve Trennis was in posession of her two sabers when learning how to jump great distances under the tutalage of her Master Sskeer around 238 BBY on Kirima.
During her Jedi Trials on Shuraden, Trennis used her lightsaber during a sparring match with her master and then to save herself from falling off of one of the needles she was tasked with climbing prior to being chased by a swarm of Ridadi
After being knighted by the Marshal of Starlight Beacon Avar Kriss, Trennis was among the numerous Jedi in attendance of the station's dedication; raising her lightsaber in the air in celebration.
Keeve Trennis defending herself on Sedri Minor
While on Sedri Minor, Trennis used her lightsaber as a double-bladed saber alongside Avar Kriss and Sskeer to defend herself from hoards of Drengir which had taken root in the planets soil. Soon after, during the same mission, she used both of her lightsabers separately to deflect blaster bolts fired at her and the rest of the Jedi by Myarga Anjiliac Atirue's forces. She subsequently used her lightsaber to disarm Sskeer to keep him from killing Myarga while under the influence of the Drengir and after doing so was forced to duel her former master until he was able to regain enough control over himself to ask Keeve to help him to convince the Drengir to stop attacking.