IPSW Portal

Choose aProduct→Choose aPlatform→Choose aVersion→ClickDownload

Download 4.3.1 (15T5565a) for Apple Watch (42mm)

Version:	4.3.1
Build:	15T5565a
Signed:	No
Size:	0.14 GB
Release Date:	2018-05-07 17:22:56
Upload Date:	2018-05-03 17:30:32

Secure download directly from Apple's servers