Black Rubberised Leather (Togo) Signature Strap

What is the material? Is it Leather? or Rubber?

I find this strap excellent and it fits my Navitimer perfectly. In HK, the weather is humid and hot in summer time and using leather strap is a nightmare. I am going to use it in summer. I am wondering whether it is leather or rubber, is it ok to use it in summer HK, or Singapore?

Black Rubberised Leather (Togo) Signature Strap

Amazing feel and quality

Love the strap, thinking of getting another in a different color.