Oskaloosa ? A nuclear density gauge and other equipment were stolen Sunday from a residence and barn near 126th Street and Rawlins Road in Jefferson County, the sheriff’s department said Wednesday.

The gauge, typically used to measure density of concrete, contains a small amount of radioactive material and could be dangerous if used improperly.

The sheriff’s department said the gauge was in a a yellow case with a radioactive symbol on it.

McAfee, Henderson and Strick Inc. is offering a $500 reward for return of the instrument.

Anyone with information is asked to call the Jefferson County Sheriff’s Department at (785) 863-2765 or (785) 863-2351.