Bi-Pin (G4, MR11 & MR16)

The Bi-Pin designation refers to various halogen products within the 12VDC and 24VDC families, commonly referred to as low-voltage halogens. These are very common in newer boats using recessed halogen interior lighting. Within the Bi-Pin family, some bulbs have an itegrated reflector and some are just small glass capsules with two pin-shaped legs protruding from the capsule.

Bulbs which fall into the Bi-Pin Category are:

- G4: Glass globe with a G4 bi-pin base with a 4mm pin spacing (shown in the foreground of the image at right).

- MR11: A glass globe centered within an integral reflector. The GU4 bi-pin base has a 4mm pin spacing, and the relector is 1-3/8" in diameter (basically a smaller version of an MR16, which is shown in background at right).

- MR16: A glass globe centered within an integral reflector. The G5.3 bi-pin base has a 5.3mm spacing, and the relector is 2" in diameter (an MR16 is shown in background at right). MR16 bulbs which have two bolt-shaped 10mm studs are only for 120VAC use.

While MR16's have a 5.3mm pin spacing and the G4/MR11 type have a 4mm pin spacing, the fact is that both types use the exact same spring-loaded socket in the fixtures themselves. This means that in most situations where there is room in the fixture, the bulbs are interchangeable.

MR11 and MR 16 halogens utilize a built in "dichroic" reflector. That is just a fancy name for a reflector that reflects light forward, while letting the infrared (heat) pass directly through the reflector and in the opposite direction of the light. With our LEDs, the reflector is redundant, but the form-factor is handy, and our MR11 and MR16 LED's are good for replacing G4 halogens in applications like bell-shaped reading lamps where the bulb orientation is on-axis, and the light needs to shine out from the end of the bulb.