A device for inserting a pre-filled or silicone prosthesis into a surgical pocket is formed from a sleeve formed of a bottom layer and a top layer attached to the bottom layer along longitudinal edges of the bottom layer and top layer. The top layer has a greater width than the bottom layer so as to form a half-cylinder shape when the sleeve is filled. The sleeve has a constant cross-sectional area along a length of the sleeve. This device reduces the chances for the implant to rotate in an unintended manner due to the non-circular cross-section of the sleeve.