Esplender (エスプレンダー Esupurendā?) is Gamu Takayama's transformation item. With it, he can transform into Ultraman Gaia and fight the monsters.
After Ultraman Gaia defeated C.O.V., he turned back into Gamu. Gamu found a strange light on the battle which he sensed was important, using a photoelectron tube he had on him, he took it. Later on, he used it to transform into Gaia a second time. Gamu later built the Esplender to properly house the Gaia force as a more suitable device. In Ultraman Gaia episode 26, Hiroya Fujimiya gave the Esplender Agul's light, transforming Gaia into Version 2. The Esplender was later drained of its power by Zogu, rendering it useless. Later in the Ultraman Gaia direct-to-video special Ultraman Gaia: Once Again Gaia, a race of advanced undersea beings restored Gaia's force.
Gaia's light in a photoelectron tube (technically the Esplender's first form)
Before the usage of Esplender, Gamu first stored Gaia's essence in a photoelectron tube while raising it to the air to transform mirroring Shin Hayata's transformation of Ultraman via the Beta Capsule.
The Esplender is the first transformation device shown to be created by human hands.
It is also the first to demonstrate the principle(s) of Transformation Devices. That being the storing and unleashing of the Ultra's essence for the purpose of transforming.