Bucket mutes attach to the rim of the bell with springs and contain cotton, foam or a similar substance. The effect is removal of high frequencies and a soft, muffled tone. Some modern bucket mutes (by JoRal for example) are designed as oversized straight mutes filled with batting, with large holes in along the side. These are held in the bell of the instrument with strips of cork, like straight and cup mutes. Players often find a trade-off between spring-style mutes, which can prevent quick transitions and cone-shaped mutes that squeeze into the bell, which can cause back-pressure. Modernized flexible spring-style clips on bucket mutes make transitioning fast and also eliminate back-pressure.