(Unicron—an ancient, malevolent entity the size of a planet—famously rebuilds Megatron into Galvatron in 1986’s The Transformers: The Movie ... Soundwave was one of the more popular G1 toys ...

and they can be used with the Soundwave and Blaster toys from the same line. Their inclusion evokes the iconic scene in The Transformers: The Movie in which Soundwave unleashes his cassettes ...