This Relion humidifier wick replacement filter fits Relion RH1300. It measures approximately 5" H x 4 1/4" ID x 6 1/2" OD x 1" and prevents surface growth and migration of mold, fungus, algae, and bacteria. For optimum performance, replace filter at the beginning of each season or every 2 months depending on use.

Honeywell HAC504 Replacement Filter For Robitussin DH-835 - B0051O7YM2