The Ingersoll Rand 23972854 inlet valve is a normally closed inlet valve used on the R4-11 (5HP to 15hp) rotary screw air compressors.
It is recommended to replace this valve every 16,000 hours or 4 years. If your compressor is slow to build air or it leaks from the inlet valve, this kit may solve the issue. Often times this is refered to as an Unloader Valve
24820409 is an OEM part manufactured by Ingersoll Rand. Ingersoll Rand used many different styles of inlet valves on their R4-11 series of rotary screw air compressors - we highly recommend calling in with your model number and serial number for confirmation this part is correct for your compressor.