From Harpic
Harpic Power Plus Deep Cleaning Toilet Tablets clean where the brush can't reach — working below the waterline and all the way into the u-bend, so no scrubbing is ever needed. Dropped straight into the cistern, each tablet delivers a powerful, continuous deep clean with every flush, killing 99.9% of bacteria and removing 100% of limescale. Say goodbye to hard-to-reach grime and hello to a hygienically fresh toilet, effortlessly.