Rainbow Filter Lid Lockring 172214 - Suits RTL, RCF & RDC style Rainbow filters - New version

Rainbow filter lockring

24 ribs on outside, marked - '172214', 'LOCK RING'. 'ON', 'OFF'
Buttress thread 

New version:
188mm OD, 170mm thread ID 
not notches.

This decrease in thread diameter 'may' make this lid too tight to fit. In this event, either the thread on the lockring and/or filter canister needs to be filed down, or complete filter replacement is required.

Original version:
188mm OD, 171mm thread ID
Had 4 square notches in the top inner flange.