Made specifically for the Dvarw attys, rings are available in stainless steel or black delrin - There are different rings for the standard plastic (PMMA) tank and also for the new upgrade glass tank - PLEASE CHOOSE CAREFULLY! 
 
PT is Is For The Standard Plastic Tank (PMMA)
GT is For The Upgraded Optional Glass Tank - THE 23-22-SS-GT IS POLISHED AND WILL NOT MATCH THE LIMITED EDITION BRUSHED FINISH
SS is Stainless Steel
BD is Black Delrin
These can also be used to reduce airflow for a tighter draw by turning to close off the slot
 
NOTE THESE DO NOT FIT THE NEW FL VERSION