Tester Zero

Tester Zero (テスター・ゼロ) is a weapon that can be used by Vexen in Kingdom Hearts 358/2 Days. It is Vexen's basic weapon, and therefore requires no Gears to be attached to him in order to wield it. In appearance, Tester Zero is almost entirely gray, symbolizing that it is the most basic of all of Vexen's weapons through the use of achromatic colors. This weapon's combo finisher is Vexen thrusting Tester Zero forward, with several hexagons appearing in front of him from where the shield was launched.

Design
Tester Zero is shaped like an upside-down heart with one circular section taken out of each side. This has the effect of making the top of the shield resemble a spike from the Nobody logo. The shield also has two more large spikes at the bottom; one protruding from each of the bumps on the heart. Tester Zero's border is silver and its face is grey.

Etymology
Tester Zero is a term usually refering to the first product being tested.