BOSTON — Die-hard Star Wars fans will need to rely on more than the force if they want to bid on an R2-D2 droid that appeared in several of the franchise’s movies.

A couple million dollars might also help.

Luke Skywalker’s lightsaber, Darth Vader’s helmet and shoulder armor, as well as imperial and rebel weapons are on the block, but the centerpiece is no doubt the squat blue, white and silver droid famous for communicating in a series of electronic beeps and squeaks.

Representing “the pinnacle of the Star Wars collecting universe,” it could fetch up to $2 million in the June 26-28 auction, according to Calabasas, California-based auction house Profiles in History. The bidding is being handled by Boston-based online auction marketplace Invaluable.

Nothing like a complete R2 unit has ever been sold at auction before, said Stephanie Connell, a London-based movie memorabilia consultant not involved in the sale.

“This is not just a normal movie prop,” she said. “This is instantly recognizable, the creme de la creme of movie props.”

Connell wracked her mind, but said she could not recall any single piece of Star Wars memorabilia ever selling for anywhere close to $2 million.

The 43-inch tall R2 unit for sale is sort of a Frankenstein’s monster of droids, pieced together over several years from different original components used in the first five Star Wars movies. There is no other known complete original R2 unit in the public domain, according to the auction house.