Fits BT-3 tube - 0.375"

Semroc Thrust Block or Engine Block for 13mm Motors Wound Craft Paper(1pk) SEM-TB-5

Semroc Thrust Block or Engine Block for 13mm Motors Wound Craft Paper(1pk)  SEM-TB-5 Wound Craft Pap…

Semroc Centering Rings Fiber BT-3 to BT-20(2pk) SEM-RA-3-20

Semroc Centering Rings Fiber BT-3 to BT-20(2pk)  RA-3-20 Laser-cut rings for centering a BT-3 tube …

Semroc Centering Ring Wound Craft Paper BT-3 to BT-5(1pk) SEM-CR-3-5

Semroc Centering Ring Wound Craft Paper BT-3 to BT-5(1pk) SEM-CR-3-5 Also used as a Thrust Block or …

Semroc Centering Ring Wound Craft Paper BT-3 to BT-4(1pk) SEM-CR-3-4

Semroc Centering Ring Wound Craft Paper BT-3 to BT-4(1pk)  SEM-CR-3-4 1 pack

Semroc Centering Rings Fiber BT-2 to BT-3(2pk) SEM-RA-2-3

Semroc Centering Rings Fiber BT-2 to BT-3(2pk)  RA-2-3 Tough Fiber 0.05" Thick