Two double A batteries.

Matt was annoyed for about 15 minutes after the great shift left him in the body of a young woman who was at the time pleasuring herself in the bath.

As he felt the dildo vibrating between his legs still stuck inside this girl's vagina he could not help himself from finishing off what she had already started and could not believe how much pleasure a bit of rubber and two double A batteries could bring as he flashed about in the water enjoying every inch of his new body.