Thermal Pad OP-8300 Spec03
OP 8300 Spec 03 is a ceramic filled silicone elastomer. It is
exceptionally soft and is suitable for applications that require
moderate thermal performance.
OP 8300 Spec 03 is electrically non-conductive and naturally tacky.
Additional adhesive is generally not required.
http://www.schlegelemi.com/upload/files/Update_TDS_Oct.2017/TDS_OP_8300Spec03Rev02.pdf