The large translucent piece that goes around all of the wires could either be a thin piece of Teflon sheet wrapped around the wires or a short length of Teflon heat shrink that was not shrunk down.
The small insulation on each individual wire looks like silicone coated fiberglass insulation.
Thicker heat shrink would work and the tape is just protecting the solder joints for the coil. TBH, that looks like fiberglass packing tape or even just fiberglass sleeves over the joints. (Fiberglass packing tape wouldn't be my first choice to protect wires like that, but something is better than nothing I suppose.)
