| Base Type | Dome | Front Crown | Rear Crown | Color | Notes | Ref. # |
|---|---|---|---|---|---|---|
| SB | R-3 | CONTINENTAL/ RUBBER WORKS U.S.A. |
W.U.TEL.CO. 7-A/ PAT.2,218,497 |
black |
| Base Type | Dome | Front Crown | Rear Crown | Color | Notes | Ref. # |
|---|---|---|---|---|---|---|
| SB | R(rubber dot)4 | CONTINENTAL/ RUBBER WORKS U.S.A. |
W.U.TEL.CO./ 22 PAT. 2,218,497 0-B |
black | ||
| SB | R(rubber dot)4 | CONTINENTAL/ RUBBER WORKS U.S.A. |
W.U.TEL.CO./ 27 PAT. 2,218,497 0-B |
black | ||
| SB | R(rubber dot)4 | CONTINENTAL/ RUBBER WORKS U.S.A. |
W.U.TEL.CO./ 32 PAT. 3061667 3-C |
black | ||
| SB | 94(rubber dot)80 | CONTINENTAL RUBBER WORKS/ ERIE PA USA |
2-D PAT-3061667 | black |