These Mighty Magnets are new and the problem is a slight discoloration or yellowing  of the white wet-side magnet casing. They are recommended for 1-1/2″ to 2″” aquarium wall thickness. The inner floating magnet dimensions are 6” x 9” and only 1-7/8 thick.

Product includes: Plastic Storage Case, Spacer Block, Instructions, and an extra Acrylic Safe Pad Set (outer magnet Felt Pad and inner magnet Algae Scrub Pad).

This product is compatible with: Replacement Pad Set (C/E), Algae Cutter Bag (D), Dozer Pad (E), and Scratch Removal Kit (E).

Always clean, inspect, and test products in an inconspicuous area of the aquarium.