Based on this product's specifications, here are some alternatives and similar models
kfa² Head Gasket 3/8" – model 961-061-85
Summary description:
Replacement head gasket by kfa², size 3/8" (model 961-061-85). Designed as a sealing component for compatible plumbing or mechanical assemblies that require a 3/8" gasket. Used to ensure tight joints, prevent leaks and maintain pressure integrity in water, gas or fluid connections where this specific gasket dimension and fitment are required.