The Hamer Company was founded by Jol Dantzig and Paul Hamer, and is now a division of Kaman Music. Hamer's most loyal customer, perhaps, is Cheap Trick guitarist Rick Nielsen, for whom the company built this electric mandocello—which, it claims, is the world's first. (That claim, by the way, isn't true; ViViTone made one as early as 1933.) At least one more of these exists.