PS4: How to get your hands on a PS4 with firmware 6.72 or lower - Wololo.net
New PS4 6.72 System Software Update Warning Firmware Problems - YouTube
Here's how to update your PS4 to 9.00 then Jailbreak, Much Better stability than 7.55, 7.02 or 6.72. : r/ps4homebrew
SONY PlayStation 4 Pro PS4 - 1TB (Firmware Version 6.72) 1 TB Price in India - Buy SONY PlayStation 4 Pro PS4 - 1TB (Firmware Version 6.72) 1 TB Black Online - SONY : Flipkart.com
PS4 PRO Death Stranding bundle 6.70 confirmed : r/ps4homebrew