The Synergy shower filter is made of durable water purification-grade 304 stainless steel. In addition, the cartridge is openable and thus refillable, so instead of replacing the cartridge you empty it and easily refill it with new purification material yourself when the material is used up. Depending on your water, there are three different types of purification material you can choose from when replacing it the first time. Upon delivery, you always receive a standard cartridge.

Standard (for normal water): High-activity coconut shell carbon + Zeolite (clinoptilolite)

Against chlorine (if you have a lot of chlorine and heavy metals in the water): High-activity carbon and KDF-55

Against iron (if you have a lot of iron in the water): High-activity carbon and KDF-90

Replacement interval for the cartridge: about every three months.

Refill material for the Synergy shower filter can be found here.