Polybutadiene Rubber (PBR) is a premium product manufactured and marketed by Reliance Industries under the brand name Relflex Cisamer. It is a high-quality synthetic rubber with a high cis content, making it exceptionally elastic and resistant to dynamic stress, thereby providing superior durability to the final product.

PBR has numerous applications in various industries, with the major application being in the manufacturing of tyre treads, tyre carcasses and sidewalls, under-treads, cycle tyres, conveyor belts, sportswear, golf balls, automotive components, conveyor belts, and shoe heels and soles. Due to its superior elasticity, resilience, and abrasion properties, PBR is also suitable for the production of flexible rollers and mechanical goods.