MaestroLamps.com also sells Bare Projector Lamps since this saves money for the customers. When it comes to Projector Lamps, there are 2 types involded; 1. Lamps with Housing / Cage / Module / Holder: This is a full lamp unit, wherein when the customer orders the lamp unit, they simply have to take out the old lamp unit out of the projector and install the new one into the projector. Always ready to fit into projector. 2. Bare Lamps / Bulbs: This is only Bare Bulb without Housing / Module / Cage / Holder. The projector bulb is usually comes inside an Module / Cage / Holder / Housing, which is used to hold the bulb and absorb the heat generated while the projector is in “ON” Mode. The actual light emitting part is the Bare Bulb. So to save cost customer can also buy only Bare Bulb, and while re-installing it into a projector, they should first install it into a old housing. Bare Lamp installation is also an super easy process, For a AC lamp, the customer should not worried about the connection types. But in case if their projector uses DC lamp, they should call our customer support who can guide you the installation process.