hard rubber
vulcanite
ebonite

He's poor company but I had my liver set on a few good, hard rubbers.

They are made out of hard wood or hard rubber.

He pulled a short strip of thin hard rubber from his vest.

The ball is made of a very hard rubber wrapped in pandanus.

I reached up for the line and hung on with my cheek pressed against the hard rubber.

It was like hitting a solid column of hard rubber.

Chapter 10 The room was small, the floor and walls of a synthetic material with a surface like hard rubber.

It was made of hard red rubber with a stainless steel handle.

The prime tyre is made from harder rubber and will last longer.

These were made of hard rubber but only standing at 6 or 7" tall.