Fragrancing gel. SmellyJelly has been formulated to provide a pleasant fragrance in fan coil and cassette units. Easy to apply, SmellyJelly is simply placed within the unit, ideally as close to the discharge point as possible. Once in position and the unit switched on the fragrance will immediately become noticeable. SmellyJelly gel blocks now survive at even higher temperatures (up to 70°C) once inside a fan coil or cassette unit… smelling even better for even longer.