Lieutenants in the Coast Guard wear embroidered, sew-on rank insignia on the collars of the Operational Dress Uniform (ODU). The choice of embroidered insignia for this working uniform is likely due to concerns that could arise from metal collar devices coming loose and creating a safety hazard (note that Coast Guard Academy Cadets and enrollees at Officer Candidate School are allowed to wear metal insignia on these collars).
To correctly position the two silver bars of the Coast Guard Lieutenant insignia on the collars, imagine a line running through the middle of the collar point, equally bisecting it. With the insignia oriented so the long axes of the bars are vertical, tilt it inboard and center it on the line, i.e., the line is now bisecting the insignia with a bar on either side. Place the insignia so that its bottom is one-and-a-half inches from the collar point.