These fill the extra space in toilet seat mounting holes (in toilet bowl), so mounting bolts fit snugly and do not move around. Helps keep your seat securely in place.
NOTE: Use with bottom mount hardware only. Not compatible with split wingnuts (which serve the same purpose).
TIP: Before installation, make sure the mounting area around the toilet seat mounting holes is clean and dry (without cleaning chemical residue). Use glass cleaner to ensure the area is squeaky clean.