keypad devices have become commonplace in everyday life . they are part of our everyday life , in the form of pocket calculators , telephones , remote control devices , and cellular phones . cleaning these keypad devices is problematic , since they have a large number of actuatable keys , due to the functions to be performed . as a mechanical interface in the keypad device , each key is a critical weak point in terms of maintaining a tight seal . an easy - to - clean keypad device , in particular an emergency call device , has a main body , an electronic assembly — which includes circuit elements and is installed in main body — a closing shell and keys , which are installed in closing shell and are designed to mechanically actuate the circuit elements . closing shell with installed keys is a first preinstalled assembly , and main body with installed electronic assembly is a second preinstalled assembly . the first and second preinstalled assemblies are interconnected such that they may be separated .