Our current cat flap's magnet is not, how shall we say, doing the biz as every time a puff of wind blows against it a cold current of air soon pervades my little office area. Yes, I cleaned the cat fluff off but to no avail. Time to get a new one "large cats and small dogs" size. The first one's magnet was useless so got another one which was also useless. Finally got one with a good magnet and installed it. Two cats went in and out no problem; unfortunately our female tubby tabby called Weasel took offence to its only slightly slimmer outline, decided she wasn't going to get through, and promptly had a wee right next to it. Cue lots of mopping and refreshing applications. We looked at each other and said in unison "We're going to need a bigger cat flap"! One has just arrived and should do the trick.