Masterline Bird Spike System - 5 inch - Polycarbonate is a cost effective, humane, spike used to deter pest birds from landing and roosting and the patented "Center Spike" prevents the birds from nesting. The Spike System has been highly effective against crows, gulls, pigeons, raptors, vulchers, and many more. Made from the highest quality unbreakable material, the spike system is easily installed using the glue line for maximum adhesion or screws. They are packaged in two foot sections which cuts the labor time in half and each section has break away points for easy sizing. Each box contains 50 ft.