Halogen Replacement Bulbs

MR11 - Halogen 10 Watt Replacement Lamp for Submersible Lights
MR11 - Halogen 20 Watt Replacement Bulb for Submersible Lights
The MR-11 is about 1-1/2" (34mm) in diameter at the widest part of the lamp
G4 Base (2 Pin with a spacing of about 4mm)
Average Lamp Life of 1500 Hours

MR16 - Halogen 20 Watt Replacement Bulb for Submersible Lights
MR16 - Halogen 20 Watt Replacement Bulb for Submersible Lights
The MR-16 is just under 2" (49mm) in diameter at the widest part of the lamp
G5.3 Base (2 Pin with a spacing of about 5.3mm)
Clear cover over lamp
Average Lamp Life of 5000 Hours

20 Watt - 12V Bi-Pin Clear Halogen Bulb
Average Rated Life (hr): 2000
Base: G4
Diameter (mm): 8.00
Light Center Length - (mm): 20.00
Maximum Overall Length - MOL (mm): 33.00
Nominal Voltage (V): 12
Nominal Wattage (W): 20

Halogen 250W Replacement Lamp for the CalPump L1C Light shown in second image