The phrase "are replacements for" is correct and usable in written English.
You can use it when discussing alternatives or substitutes for something, indicating that one thing can take the place of another.
Example: "These new software tools are replacements for the outdated programs we used previously."
Alternatives: "serve as substitutes for" or "act as alternatives to".
Almost all of the current cast members — and virtually the whole class of German schoolboys and schoolgirls stomping the Eugene O'Neill stage are replacements for the originals — look as if they have yet to meet their first pimples.
In March Atwal also warned that tablets would begin cannibalising sales of low-end PCs such as netbooks – a scenario that has begin to play out in the mature markets of North America and Europe, where between 80%to90%0% of PC sales are replacements for existing machines.
Some viewers wrote back and complained that today's sport utility vehicles are replacements for the traditional wagon.
Also in the works are replacements for Chrysler's midsize cars, the Sebring (Chrysler) and Stratus (Dodge), which currently account for 200,000 annual sales.
Active D-lighting system 3D Color Matrix Metering II (this and the above thing are replacements for post-processing, which is both fun and rewarding, so no need for 'em) Stop-motion movie mode (probably fun).
Obviously there are replacements for the media browser, but if Mewbox wants to make it big (like Wham!), they're going to have to be patient, because even as Android blows up, it's going to take some time before people start relying on it as a music playback device.
The first applications of graphene are likely to be replacements for rare or less efficient materials in electronics.
While such products weren't meant as total food replacements, they were replacements for specific foods meant to save us time and money – and even help our health.
The two greatest quarterbacks in recent memory were replacements for established starters who showed signs of struggling.
