These nylon vault key-hole signals are colorfast, non-chip and reusable. Prongs securely engage lock tumblers for tight key-hole fit. Witdraw and use again as needed. Offset head properly centers signal over key-hole opening. Color denotes category: RED - officially sealed by court or bank order, BLUE - rent overdue, WHITE - box for rent, BLACK - death, GREEN - special uses, ORANGE - more than one person present to open box. One universal size - 7/8 inch prong with 1/2 inch head designed to fit most popularly used brand locks. Packed 25 signals of one color per box.