Decooo.be Anti-Collision Stickers to Prevent Bird Strikes on Window Glass - Set of 17 Silhouettes - Color White - Window decals Set of 17 bird silhouettes of different shapes and sizes (see picture for details). The bird silhouettes prevent bird strikes. Glass panels, verandah doors or bay windows can act like mirrors with the sun rays reflection. Bird silhouettes are coloured on both sides. So, colour of the stickers is visible both from the outside as well as from the inside. However, it is advisable to apply them on the outside surface of the window. Guaranteed high quality materials with long-lasting adhesiveness (will not fall off over time, resistant to rain, freezing weather conditions and cleaning agents) and long-lasting colour (will not fade over time either). This product contains 2 sheets with bird silhouettes. For an easier application, peel the excess vinyl (around the birds) off and pull it all off the paper support sheet. After that, just peel the birds off and place them on your glass with clear water.