The eBay seller says: Early Bell Labs Condenser Microphone. Its dimensions are 16 inches × 4½ inches. Net weight 6.6 pounds. I am told it is an early Bell Labs Condenser Microphone. Sure does look like a Western Electric Type 394. Please correct me if I am wrong and I will relist or make corrections accordingly. Please take a look at pictures below. Plenty of pictures from all angles so you can see what you are buying. Tubes inside are 1 × 6F5 and 1 × 6C5. The transformer number is F 21. That is all the information I can gather from this mic. There is also a number on the mic itself. You can see this number clearly. I removed it and the inside showed the same number. Everything appears to be original and stock. All old caps and old wiring. Nothing replaced inside. This one will be sold as is due to inability to test.