Fits ST-20 tube

Semroc Centering Rings Plywood ST-16(BT-60)20 to ST-20(2pk) SEM-CR-16-20P

Semroc Centering Rings Plywood ST-16(BT-60) to ST-20(2pk)  SEM-CR-16-20P 2 pack ID= 1.64" …

Semroc Centering Rings Fiber ST-7 to ST-20(2 pieces set with engine hook slot) SEM-CR-7-20EH

Semroc Centering Rings Fiber ST-7 to BT-20(2 pieces set with engine hook slot)   SEM-CR-7-…

Semroc Centering Rings Plywood LT-115(BTH-52) to ST-20(2pk) SEM-CR-115-20P

Semroc Centering Rings Plywood LT-115(BTH-52) to ST-20(2pk)   SEM-CR-115-20P Laser-Cut Li…

Semroc Centering Rings Fiber 3x ST-7 to ST-20(2pk) SEM-CR-3x7-20

Semroc Centering Rings Fiber 3xST-7 to ST-20(2pk)   SEM-CR-3x7-20 Laser-cut rings for cent…

Semroc Centering Rings Plywood BT-50 to ST-20(2pk) SEM-CR-50-20P

Semroc Centering Rings Plywood BT-50 to ST-20(2pk)   SEM-CR-50-20P Laser-cut rings for ce…

Semroc Centering Rings Fiber BT-20 to ST-20(2pk) SEM-CR-20-20

Semroc Centering Rings Fiber BT-20 to ST-20(2pk) SEM-CR-20-20 Laser-cut rings for centering a BT-20 …

Semroc Fiber Block BT-20(1pk) SEM-FB-20

Semroc Fiber Block BT-20(1pk)   SEM-FB-20 Fiber Blocks are used as lightweight plugs, …

Semroc Plywood Block or Bulkhead for ST-20 tube(2 ring set)(same CR-20P) SEM-PB-20(ST)

Semroc Plywood Bulkhead or Block for ST-20 tube(2 ring set)  SEM-PB-20(ST) Used as lightweight…

Semroc Centering Rings Fiber BT-5 to BT-20(2pk) SEM-RA-5-20

Semroc Centering Rings Fiber BT-5 to BT-20(2pk)  SEM-RA-5-20 Laser-cut rings for centering a BT…

Semroc Centering Rings Fiber ST-9 to ST-20(2pk) SEM-CR-9-20

Semroc Centering Rings Fiber ST-9 to ST-20(2pk)   SEM-CR-9-20 Laser-cut rings for centerin…

Semroc Centering Rings Fiber ST-7 to ST-20(2pk) SEM-CR-720

Semroc Centering Rings Fiber ST-7 to ST-20(2pk)   SEM-CR-720 Laser-cut rings for centerin…

Semroc Centering Rings Fiber LT-115(BTH-52) to ST-20(2pk) SEM-CR-115-20

Semroc Centering Rings LT-115 to ST-20(2pk)  SEM-CR-115-20 Laser-Cut Tough Fiber Rings to Cente…

Semroc Centering Rings Fiber ST-10 to ST-20(2pk) SEM-CR-10-20

Semroc Centering Rings Fiber ST-10 to ST-20(2pk) SEM-CR-10-20 Laser-cut rings for centering a ST-1…

Semroc Centering Rings Plywood BT-50 or BTH-52(LT-115) to ST-20(2pk) CR-50/52H-20P Discontinued

Semroc Centering Rings Plywood BT-50 or BTH-52(LT-115) to ST-20(2pk)  CR-50/52H-20P Light Pl…

Semroc Centering Rings Plywood BT-20 to ST-20(2pk) SEM-CR-20-20P

Semroc Centering Rings Plywood BT-20 to ST-20(2pk) CR-20-20P 2 pack ID= 0.738" OD= 2.0" Thickness: …