Based on this product's specifications, here are some alternatives and similar models
Boiler Trap McAlpine HC7-FUN 3/2" x 50 mm, waste outlet for water heater
Summary description:
McAlpine HC7-FUN is a boiler trap designed for connection to domestic water heaters. It features a 3/2" x 50 mm connection size for waste discharge and is intended to provide a sealed outlet that prevents odors while allowing condensate and drain-off from boilers. Suitable for use with electric and gas water heaters where a compact, dedicated waste trap is required.