Includes internal snap ring.
Smoke well is 1.875" deep by 1.25" wide smoke well (behind snap ring) with 1/4-20 thread attachment point on top.
Is capable of head-end ignition with a modified smoke grain and drilling a small 1/8" hole through the bottom of the 1/4-20 threaded hole.
The liner shoulder incorporates a liner sealing o-ring acting the same as a seal disk found in other brands. This is designed for use strictly with convolute phenolic liners. Spiral wound liners must not use this o-ring.
The external threads are 5/8"-11 UNC 2A and 1.5"-18 UNF. They are in place for future accesories that may be developed. For now, they are for the hobby machinists out there to create their own methods of connecting electronics bay mounts, locking rings and other accesories and airframes used in ultra high performance, sub-minimum diameter flights.
The bulkhead extends approximately 1.78" from the end of the case.