The Brinsea OvaView Standard egg candler is designed to be either hand-held or can be left on a work surface. Battery powered for convenience it uses high output high efficiency LED illumination ? so no bulbs to replace and no concerns about overheating the eggs during inspection. Supplied with a flexible black ring to seal against the egg shell and a set of 4AA batteries, it can also be used with rechargeable AA batteries. The OvaView Standard is suitable for monitoring the embryo development of pale, plain shells (most species of hen, duck, goose, etc.) For darker and mottled eggs we recommend the OvaView High Intensity. Like all Brinsea products they come with a full 2 year warranty.