It fits most standard wall-mounted tub spouts, including ones with a diverter knob on top. Two stretch bands (large and small) come in the box. It won't fit waterfall spouts, deck-mounted faucets or freestanding tub fillers. Not sure? Send us a photo of your spout at hello@purepuddle.com.

The cartridge is designed to reduce chlorine in the water that fills the tub, so bath water smells less like a pool. It's a filter, not a medical product, and it isn't meant to treat any skin condition.

About every 2 to 3 months with a daily bath. Hard water or two kids in the tub means sooner. Replacement cartridges are sold here in singles and 3-packs.

No. It changes color as the water warms, so you get a quick visual hint. Always check the water with your hand or elbow before your little one gets in.

Take the cartridge out and put the silicone body in the top rack of the dishwasher, or rinse it with warm soapy water. Let it dry between baths if you can.

Orders ship within 1 to 3 business days and usually arrive in 5 to 8 business days with tracking. US shipping is free on every filter.