Cui using his green lensed scouter.
Scouters are a item that allows someone with no special ability to read power levels. Scouters are first seen when Raditz arives on earth. Some Scouters are apparently very fragile as Zarbon's Scouter broke when Vegeta powered up against Cui with a Power Level of 24,000, while others like the Ginyu Forces' can go up to 530,000.