This is a pair of reusable, no detergent, eco washing balls - they each last up to around 1,000 loads. Simply place the ball on top of your laundry in the washing machine and start the program as normal. These specially designed balls contain all the things you need for a perfect wash, over and over again, cleaning your clothes first time, every time and leaving them fresh and with no residual detergent. During the first few washes you'll probably see some froth and suds in the wash. This is perfectly normal and is just the residual washing powder coming out of your clothes. It's up to you whether or not you use a fabric conditioner with your washes - the eco washing ball doesn't leave a smell. To allow the eco washing balls to work efficiently, please don't overload or cram your washing machine - about full seems to work best (and does for regular washing powders as well). For even better results, leave the eco washing ball outside in the sun (always assuming we get sun in the UK - a window sill works fine) for an hour or so once a month - this gives it even better performance. Works well in hard and soft water areas. Stubborn stains may need a helping spray before washing, just as they do with normal washing powder/liquid.