IF you are trying to replace a pull on your jacket:
There MIGHT be a 4 on the back of the zipper head on your COIL zipper tape.
This PROBABLY means you have a 4.5mm coil zipper.
These are auto-lock pulls with a 5/8" handle or pull.
The AUTO-LOCK means the zipper head automatically locks or stops when you stop pulling.
IF you don't have a head left on your zipper, order a #4.5, #5, & #7 for coil because these are the most often used in jackets with a COIL zipper. No, there is not a STANDARD or NORMAL zipper used in a jacket. So you will need to test-drive the different heads to see which will open & close your zipper.
Also order a top stop to replace the top stop on your zipper you need to pull of to get the head off.
I try to stock 90% of the pulls that will fit, but impossible to carry all of them....... SO if you can't determine what sort of zipper you have on your jacket, text me a picture of your zipper at the BOX & PIN end (bottom). Also with a picture of the zipper head. I'll see if I can identify it.
My CELL PHONE: 970.231.1434
PLEASE understand that I get over 100 texts per day, 200 phone calls before 10am in Colorado & yes, over 1,000 emails a DAY, or there are a whole lot of broken zippers out there. AND I leave my phone at the warehouse on the weekends so I'll respond when I get to work on Mondays.
I personally answer all these missives. PLEASE do not leave me a message on my phone & an email & a call. It will just take me longer to get back to you. Unless your smart phone is smarter than you are, TEXT the pictures. TEXT me messages.
I am HAPPY to give you my expertise from 65 years of sewing, school of hard knocks, & 30+ years of being the Zipper Lady. But you need to know, I DON'T KNOW EVERYTHING & I'm just giving you my best guess.
FYI = Zipper Pulls are indigenous to the tape of zipper. So a #5 pull for Metal zipper will not fit on a #5 COIL zipper or a #5 MOLDED tooth zipper tape. The "5" means that the coil, molded tooth or metal tooth is 5mm across when closed but the pull or slider or head (the part that runs on the zipper) is made differently for different types of zipper.