Blutz Wave Amplifier
From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
The Blutz Wave Amplifier was a machine that amplified natural Blutz Waves by 1000%. It was built by Bulma while she was under Baby's control. Saiyans may transform into Great Apes even without a tail if the energy given by Blutz Waves is correctly amplified, and therefore this machine may be used on tail-less Saiyans.
This machine was used to turn Baby into a Great Ape. Later, during the fight against Omega Shen Long, Vegeta used the same machine to advance to Super Saiyan 4 since he lacked a tail.
It appears that an artifically high concentration of Blutz Waves can also be used to re-energize a Great Ape. Using the Amplifier, Bulma was also able to bring Great Ape Baby back to full power after he been knocked out by Goku.
Gallery
Bulma using the Blutz Wave Amplifier.
Blutz Wave Amplifier in action.
