Fits ST-13 tube

Semroc Plywood Block or Bulkhead for ST-11 tube(2 ring set) SEM-PB-11

Semroc Plywood Bulkhead or Block for ST-11 tube(2 ring set)  SEM-PB-11P Used as lightweight bul…

Semroc Plywood Block or Bulkhead for ST-9 tube(2 ring set) SEM-PB-9

Semroc Plywood Bulkhead or Block for ST-9 tube(2 ring set)  SEM-PB-9P Used as lightweight bulkh…

Semroc Plywood Block or Bulkhead for ST-8 tube(2 ring set) SEM-PB-8

Semroc Plywood Bulkhead or Block for ST-8 tube(2 ring set)  SEM-PB-8P Used as lightweight bulkh…