Based on this product's specifications, here are some alternatives and similar models
Backflow prevention valve ARCO 191106, threaded 1 1/4" F x 1 1/4" F
Summary description:
ARCO backflow prevention valve model 191106 with female threaded connections 1 1/4" x 1 1/4" (GW x GW). Designed to prevent reverse flow and contamination in potable water or fluid systems, it fits inline plumbing installations with matching 1 1/4" fittings. Suitable for use in domestic and light commercial water supply lines where backflow protection is required.