Semroc Plywood Bulkhead or Block T-3.0"(2 ring set) SEM-CR-3.0P
Used as lightweight bulkheads for gluing on the end of a T-3.0 coupler, one ring fits inside the coupler and one on top to match the ID of the tube.
Hole for Screw Eye #10(SE-10)
Thickness assembled: 0.25"
Diameter: 3.01" and 2.93"
Made in the USA