729/Friendship - Battle II Soft is a new tacky rubber, developed to fit well on the backhand. Engineered with 729's EPS (Energy Preset System) Technology. With a softer sponge, you as a player get longer contact with the ball in each stroke. More control and maintained grip make Battle II Soft the most controllable rubber in the Battle series. Sponge hardness: 37. Sponge thickness: 2.1mm.
ITTF Info: https://equipments.ittf.com/#/equipment_preview/racket_coverings/2157