There are Polybutadiene rubber Russian origin. SKD-2 Voronezh Hi Cis min 90% mooney 41-49 NON-stainning SKD-EF Hi Cis min 90-92% mooney 41-49 NON-stainning SKD-Li Nizhnekamsk low-cis 38-42 % polybutadiene rubber mooney 50 for shes,tyres,ball..application.