4D21 - 4X150 Vacuum tubes
| 4-65A/4D21 | $61.00 | |
| 4-125A/8165 | $86.00 | |
| 4-250A/5D22 | $151.00 | |
| 4-400A | $201.00 | |
| 4-1000 | $201.00 | out of stock |
| 4AU6 | $4.00 | |
| 4AV6 | $4.00 | |
| 4B24 | $81.00 | |
| 4B25 | $19.00 | |
| 4B26 | $21.00 | |
| 4B31 | $61.00 | |
| 4B32 | $19.00 | |
| 4BA6 | $4.00 | |
| 4BC5 | $4.00 | |
| 4BC8 | $4.00 | |
| 4BL8 | $4.00 | |
| 4BN6 | $4.00 | |
| 4BQ7A | $4.00 | |
| 4BS8 | $4.00 | |
| 4BU8/4GS8 | $4.00 | |
| 4BZ6 | $4.00 | |
| 4BZ7 | $4.00 | |
| 4C29 | $9.00 | |
| 4C35 | $101.00 | |
| 4CB6 | $4.00 | |
| 4CE5 | $4.00 | |
| 4CM4 | $6.00 | |
| 4CS6 | $4.00 | |
| 4CX250B | $126.00 | |
| 4CX250F | $101.00 | |
| 4CX250R | $121.00 | |
| 4CX250A | $111.00 | |
| 4CY5 | $4.00 | |
| 4D21 | $73.00 | |
| 4D22 | $71.00 | |
| 4D32 | $51.00 | |
| 4DE6 | $4.00 | |
| 4DK6 | $4.00 | |
| 4DT6/A | $4.00 | |
| 4.00E+27 | $39.00 | |
| 4EH7 | $4.00 | |
| 4EJ7 | $4.00 | |
| 4ES8 | $4.00 | |
| 4EW6 | $4.00 | |
| 4GJ7 | $6.00 | |
| 4GK5 | $4.00 | |
| 4GM6 | $4.00 | |
| 4GS7 | $5.00 | |
| 4GS8/4BU8 | $4.00 | |
| 4GX7 | $5.00 | |
| 4GZ5 | $4.00 | |
| 4HA5/4HM5 | $4.00 | |
| 4HA7 | $4.00 | |
| 4HC7 | $4.00 | |
| 4HM5/4HA5 | $4.00 | |
| 4HM6 | $4.00 | |
| 4HQ5 | $4.00 | |
| 4HS8 | $4.00 | |
| 4HT6 | $4.00 | |
| 4HTF4 | $11.00 | |
| 4JC6A | $4.00 | |
| 4JD6 | $4.00 | |
| 4JH6 | $5.00 | |
| 4JL6 | $5.00 | |
| 4KE8 | $4.00 | |
| 4KF8 | $4.00 | |
| 4KN8 | $6.00 | |
| 4KT6 | $4.00 | |
| 4LJ8 | $5.00 | |
| 4LU6 | $4.00 | |
| 4MK8 | $5.00 | |
| 4MP12 | $7.00 | |
| 4MP26 | $8.00 | |
| 4RHH2 | $4.00 | |
| 4X150A | $41.00 | |
| 4X150D | $41.00 | |
| 4X250B | $41.00 |
Other tubes to choose:
01A - OZ4
1A1 - 1Z2
2A - 2Z
3A2 - 3V4
4D21 - 4X150
5AR4 - 5Z4
6A3 - 6ZY5
7A4 - 11Y9
12A - 12Z5
13CW4 - 90C1
100 - 9006
A - Z series tubes