see Birds From The Comfort Of Your Armchairvoted Past Best Buy In Which? Magazineno Tools Necessary; Just A Bit Of Water To Hold Suckers Onto The Window robust Feeder Hook Which Attaches Seamlessly To The Outside Of The Window By Means Of Two Strong Sucker Pads.these Two Strong Suckers Adhere To Window Panes To Hold Feeders Filled With Seeds Even At 700g In Weight. No Tools Necessary To Hang Up.at Least 15cm Distance Between Hanging Point & Window Means That Birds Will Not Smear The Window Glass While You Enjoy Watching Them Close Up.made From Tough Long-lasting Polycarbonate; Lasts For Years & Years.dimensions: H40.2cm X W2cm X D16.8cm.