Review on Extra Long M8 (8mm) Baby Gate Guru Stair Banister Adapter Y-Spindle Rods 2 Pack for Pressure Mounted Safety Gates - Ideal for Babies and Pets (8mm, White) by Lynn Woodcock

Good idea in theory to avoid drilling into railings on a more permanent installation. but found that this product does not work. With real pressure on the pivoting gates, they slid forward. With enough pressure, the gate can be pushed out completely and of course this can pose a danger for your child who could fall down the stairs. Probably works well enough as a surface deterrent, but I wouldn't trust it to counter real violence. We ended up buying a hardware mounted (i.e. not pressure mounted) gate that actually screws into the wood railing. Why risk your child's well-being? A few years later patch the railing and you're done.