Three versions to choose from, each with varying length.
Version 1: 3.0" or 7.8 cm
This is the stock version of RAM Combat, with open bottom, #M370
Version 2: 3.2" or 8.2 cm
This works with RAP4 P99, RAM Combat, RAM X50 or P226, #9701A
Version 3: 3.6" or 9.8 cm (longest)
This is stock version of Desert Eagle, RAP17, and later RAM X50 or P226, #2701
(Early version of P226 has Version 2 Cylinder Cover)