Rubber Sticky Stuff comprises an unsupported rubber resin adhesive extruded onto a release paper in the form of an easy-to-apply roll.  So you can cut off a strip, roll it into a ball.

Rubber Sticky Stuff provides a fast, clean and highly versatile method of forming a permanently flexible bond between two substrates without the need for priming, mixing or curing of liquid adhesives. It will form a near-immediate bond to a wide range of substrates, including metals, plastics and ceramic materials. Removable, pull away slowly to get the tape to release.

It is amber in colour, 1mm thick on a 20M roll, and available in 3 widths 12, 19 and 25mm.

Sometimes referred to as Gorilla Snot in the US, in NZ this is usually called sticky stuff.