IPSW Portal

Choose aProduct→Choose aPlatform→Choose aVersion→ClickDownload

Download 5.3 (16U5537b) for Apple Watch Series 4 (40mm, LTE)

Version:	5.3
Build:	16U5537b
Signed:	No
Size:	0.1 GB
Release Date:	2019-05-28 17:13:11
Upload Date:	2019-05-23 16:41:28

Secure download directly from Apple's servers