I am aware of two informal Loop Hook width baselines … Standard and Trimline. But even within those two classes the O.D. of the the looped frontwire varies by wire gauge (light, medium and heavy wire) resulting in 6 dimensional standards. And to me this white Flatback Slatwall Loop Hook for ear bud headphones appears even narrower than Trimline. Where the hell is my tape measure when I need it? In any event, if you have a precise Loop Hook OD requirement better talk directly with your manufacturer or ask for samples. Luckily carded merchandise for Loop Hooks is rarely so precisely dimensioned or demanding.
For Headphone Merchandising and Fixtures by Title see…
“Loop Hook Width Standards for Ear Buds” (This Post)
“Skullcandy Branded Loop Hook Locks”
“Headphone Hook Category Definition”
“How to Thwart Locking Loop Hooks”
“Headphone Head Form in Wood”
“Bolt-down Headphone Stand“
“Selling Surround-Sound Earmuffs”
For all Headphone Merchandising and Fixtures resources…
“Headphone Fixtures and Merchandising Pinterest Board“ summary.
“Headphones Index Page” for all resources and links.