JBL 2445j Diaphragm

[retro soulman]

Hello there! im ready to buy a pair of 2445j drivers for my jbl 2365 horns. The guy who sell the drivers send me a photo of the diaphragms and i notice this line threw the diaphragm as u can see from photos... what it could be ?6170861709 :confused:

[1audiohack]

I've never seen that but it doesn't look like anything I would worry about.