Each PoochPad contains Microfine fibre technology and a built-in antimicrobial agent to control odours. The agents are designed to inhibit the growth of Proteus bacteria which is present in urine and would normally multiply and create ammonia as a by-product & this is what causes a strong smell of urine. Washes over 300 times Stain resistant Liquid will not leak through absorbs up to 4X it s own weight in liquid!!!