Extension Devices enable you to reach even the highest, most remote smoke detectors quickly and easily without the use of ladders. These devices consist of two units: the Head Tube, which grips and triggers the aerosol can; and the Extension Arm, which serves to extend the range of testing operations. This versatile set of accessories allows you to test the smoke detectors at elevations of 10 to 34 feet (3m.-11m). Use with N-30-Head Features: 50" Extensions Poles for use with N-30 Dispenser Up to (5) N-59 can be used with N-30 Dispenser to reach a maximum of 34ft Not compatible with Enclosed Delivery Equipment Instructions: Remove Cap from base of N-30 and insert rod at top of N-59 into base of the N-30. Slide trigger on N-59 to activate aerosol Up to (5) N-59 units can be added to a N-30 for additional reach, by removing cap at bottom of N-59 by inserting the rod into the bottom of the N-59 and turning clockwise until tight. Always use the trigger on the bottom N-59 unit to activate the aerosol.