As noted in previous posts, this valve is a good replacement for the Norgren valve that controls the step and stair slide cover.
Amazon.com: TAILONZ PNEUMATIC 1/4"NPT Solenoid Valve 12V/24V/110V Single... (https://www.amazon.com/dp/B081PTW87K?ie=UTF8&tag=foreforums-20)
At $17, it is a good option for replacement as well as keeping a spare. One thing I found was that the old Air Mufflers were 1/4"NPT and this replacement uses 1/8"NPT filters. There was no way to adjust the air flow to control the speed/force of the stair or slide. I found these 1/8" fittings from Grainger that fit perfectly and allow adjustment to control the actuator.
SPEEDAIRE Screwdriver Adjustment Exhaust Port Flow Control, 1/8 in NPT Valve... (https://www.grainger.com/product/SPEEDAIRE-Screwdriver-Adjustment-Exhaust-1EJU2)
These two together make for a simple repair for under $30 total.