Bi-directional, vertical response impact indicator detects mishandling of products turning transit or storage. Devices turn bright red when an impact occurs. Activate devices by removing adhesive liner. Small, 1 2/3 x 1 2/3" indicator with optional, 3 3/4 x 3 3/4" label for added visibility. Unique serial number for tamper-proof tracking. Companion labels SHWCL (sold separately) inform handlers of the proper procedures to follow when in receipt of damaged shipments. Alert Tape SHWAT (sold separately) warns that package is being monitored.