We decided to differentiate our absorbency by the number of regular tampons' worth of liquid they can absorb. For each of our styles, you'll see the number of tampons associated. Choose the highest absorbency if your flow is heavy and you want to free bleed wearing them alone. If you have a lighter flow, or just want a backup to wear with a cup or tampon, our lighter absorbency styles might be just what you're looking for. Here’s a quick rundown: 4-5 tampons' worth of absorbency: Equivalent to 40-50mL. When to use: Alone on your heavy days - usually on the second and third day of your period when your flow is the heaviest. Also in the first week of postpartum. Or if you have medium bladder leaks. 2-3 tampons' worth of absorbency: Equivalent to 20-25ml. When to use: Alone on your light-moderate period days, or as back-up on your moderate-heavy days. Also great for postpartum (after the first week), or for light bladder leaks. 0.5 tampon's worth of absorbency: Equivalent to 5ml. When to use: Alone on light period days (usually the last day of your periods, or when you aren't sure they are coming yet or they are truly gone!), as backup to other products, or for sneaky leaks, sweat & discharge.