Fluke tlk290 socket probe tip set fluke fluke tlk the fluke tlk290 flexible socket probe tip set is designed for motor and three phase sockets the probe tips have flexible measuring points which can be safely placed into 4 to 8mm sockets for use with shielded 4mm test leads such as a href https www rapidonline com cables connectors 119325 fluke tl224 a safe contact for example with plugs of the type cee 16 a and cee 32 a the set contains three flexible sockets probe tips as well