The tool ZB6Y905 is done for extracting the bulbs and Tightening and slackening the bezel.Not For Tightening of Nuts.

The tool ZB6Y906 is a metallic part done only for screwing and unscrewing the nuts.

User have to use the metal assembly tool reference ZB6Y906 to tighten the nut with a torque less than 0.8 Newton meter for
securing Harmony XB6 on to the body. Incase,the bezel of the Harmony XB6 slacks or loosen,user have to use reference ZB6Y905
for tightening the bezel and having additional ability to extract the bulb from light block in case of Illuminated Pushbuttons and Pilot Lights.

Refer to catalogue pages of Harmony XB6 Accessories showing the pictorial view of references ZB6Y906 and ZB6Y905.