The description for this jump/break cue says:
The joint is wood to wood with a quick release pin. The 2nd Joint is at the base of the points to break down for jumping (or for use as a short cue).
The diameter of the smooth part is 7mm, and the diameter at the threads is 9.4mm. The pin looks like it could be a Viking quick release, as shown here:
What’s My Joint Style?
Delve into the function of pool cue joints. Learn about different materials & pins and how they impact the feel of each shot you take.

I bought the cue at billiardwarehouse:
BW Jump Break Pool Cue with 2 shafts - 2nd Generation
BW Jump Break with 2 Shafts - 2nd Generation Pool Cues, custom pool cues, cue cases and Billiard Accessories at The Billiard Warehouse.
www.billiardwarehouse.com
Thanks
Last edited: