One owner of still-working level switches manufactured by Magnetrol International, Aurora, Ill., could win a $500 gift card to Amazon and bragging rights for winning the “Just Can’t Stop a Magnetrol” contest.

The switch manufacturer invented and introduced the first mechanical buoyancy switches to the process industries more than 80 years ago. The company seeks the “hardest-working, longest-lasting level switches still in operation,” and the owner of the winning switch also will receive a replacement for free.

Magnetrol switch owners can visit between May 1 and October 31 to submit the device's age, its application and a photo to be eligible to win. The first-place winner will receive the $500 gift card and mechanical buoyancy switch. The second-place and third-place winners will receive a $300 and $100 Amazon gift card, respectively.

First- and second-place prizes will be awarded based on the age of the unit and a description of the application in which the unit works. The third-place prize will be awarded based on a random drawing of all qualified entries.