14k white gold,  this adjustable box chain measures a width of 0.60 millimeters.  The 18 inches can also wear as a 16”,  and the 20 inches can also wear as an 18 inches chain secured with a spring ring clasp. 
Product Details:
Chain Information : 
|  Metal :  | 
 14K White Gold  | 
| Chain Type :  | 
Box | 
| Clasp :  | 
Spring Ring | 
| Width :  | 
0.60 mm |