Fuel sump tester mount for 4 inch tube testers.  6 inches is the total length of the tester from phillips head to the top.   Attaches with Velcro.  Recommend 3M dual lock velcro or similar.  Velcro not included.  The price is for one mount.   Material is ASA plastic and is UV resistant.
 
works with these:
https://www.aircraftspruce.com/pages/ps/fueltesters/shortfuel.php
https://www.aircraftspruce.com/pages/ps/fueltesters/gasoholTester.php