Phone charms (also phone danglers, phone lanyards, phone chains and phone straps) are charms that are connected to a mobile device either via a phone connector or silicone plug that fits into the jack port sometimes provided with circle cotters and a lobster clasp, or a small strap knotted with a cow hitch knot, or a lanyard. Some phones may have a loop hole through which a strap can be attached or a phone case may be needed for the strap in phones that lack a loop hole. In Japan, they are known as "keitai straps" (携帯ストラップ). Phone straps have now become a cultural phenomenon beyond their basic utilities, and they may be themed with famous characters such as Hello Kitty. Phone straps may also serve additional functions, such as screen cleaning.