These walkie talkies in the shape of a Star Trek Communicator were promotional items from Crest Toothpaste from the 1989 Release of Star Trek V: The Final Frontier.
The reverse of the Walkie Talkies state it's a Star Trek Communicator Model: 652 manufactured in Taiwan.
The walkie talkies have a manual flip open grill and a on and off switch at the top with an telescoping antenna. There is a pushbutton on the side to communicate with the other Communicator Walkie Talkie.
They were more than likely sent to Mr. Shatner for his archives from Paramount Marketing as part of the promotional items from the movie.
They will be mylar bagged and sealed with an Archives Sticker.