Technical specifications:

Type: Xenon
Shape: TL1.5
Voltage: 3.5V
Amperage: 630 mA
Wattage: 2.2W
Lifespan: 80 hours

Compatible with:

Specific models:
Welch Allyn AudioScope 23000, 23020, 23040 and 23300

Compatible equipment: AudioScope

Technical specifications:

Type: Halogen
Shape: T1 1/2
Voltage: 3.5V
Amperage: 380 mA
Wattage: 2.7W
Diameter: 4.8 mm
Lifespan: 17 hours

Compatible with:

Specific models:
Welch Allyn 11620, 11630, 11720, 11730, and 11735

Compatible equipment: Otoscope

Technical specifications:

Type: Halogen
Shape: T3
Voltage: 3.5V
Current: 750 mA
Lifespan: 50 hours
Base: Bi-pin (assuming G4, I can confirm if you want)

Compatibility:

Equivalent / replacement models:
Welch Allyn 08200

Compatible with Welch Allyn models:
18200 Streak
18235 Streak
18245 Streak
Elite Streak

Applications: Use in otoscopes and ophthalmoscopes

Compatible Welch Allyn Lamp 00300-U for use in laryngoscopes.

Designed to provide reliable performance in clinical examination equipment, this halogen lamp is fully compatible with Welch Allyn devices. Ideal for laryngoscopes and fibre optic equipment.

Technical specifications:

Type: Halogen
Shape: T3
Voltage: 3.5 V
Current: 810 mA
Lifespan: 20 hours

Compatibility for:

Welch Allyn Models: 60835 and fibre optic devices

Compatible equipment: Laryngoscopes, fibre optic

Compatible Lamp Welch Allyn 03900 for Ophthalmoscope Applications

Technical Specifications:

Type: Halogen
Shape: T1 1/2
Voltage: 2.5 V
Power: 1.65 W
Current: 660 mA
Diameter: 0.19" (≈4.8 mm)
Color Temperature: 3125 K
Lifespan: 20 hours

Compatibility for:

Series: 03900

Specific models: Welch Allyn PocketScope 11110, 12810, 13000

Other series and models: Not specified

Compatible equipment:
Ophthalmoscope