TechPowerUp published a review on the Razer Viper V2 Pro Gaming Mouse
A quote from the article:
With the Viper V2 Pro, Razer revises the Viper Ultimate across the board: it now has a weight of just 58 g, comes with Razer's new industry-leading Focus Pro sensor capable of 30,000 CPI, offers up to 80 hours of battery life, and uses Razer's third-generation optical switches for the main buttons.Razer Viper V2 Pro Gaming Mouse Review