Emma the bra

John saw Emma perusing for items at a farmers market that was close to the sex shop. He focused for a second, aiming the swapping gun at Emma. He pulled the trigger, causing a beam to hit Emma directly in the chest. She had no reaction since the item she was going to be swapped with hasn't been shot yet.

John then turned his attention to a sexy red lace bra on one of the hangers in the shop

He fired the swapping beam at the bra, while keeping an eye on Emma.

She immediately zapped away from the farmers market and was now standing right where the bra was. Furthermore, she was now wearing said bra, but only the bra, no panties. She was standing stiffly at attention, a blank smile on her face.

John had designed the gun so that the beam is also capable of manipulating the density of any object to match the general weight of whatever it was being swapped with. He picked Emma up to test this and sure enough, instead of weighing the general weight of a human, her weight was reduced to a mere 5 ounces. She was also flexible to the point that her body could wrap around anyone's breasts, acting as a human "bra".