Abstract: Improved means are provided for supporting a container of effusive material within a cathode ray tube wherein the container is located at the terminal end of a resilient longitudinal positioning member attached to the electron gun assembly. The supportive means includes at least one support placement means which projects forwardly from the container as a directional continuation of the positioning member. Associated with the support placement means is a rotatable member, the peripheral surface of which tracks in a direction common with the directional trend of the positioning member. The rotatable member, which may be formed of insulative material, effects facile positioning with a minimum of abrasion and positive spatial supportive placement of the container relative to the wall of the envelope.