Product details:

These T-shaped miniature light bulbs have a miniature bayonet base, sometimes known as a BA9s base. There is one contact on the bottom of the base. The base has lugs on either side that lock the bulb in place when the bulb is pushed into a compatible socket and twisted.T-shaped miniature light bulbs are shaped like a tube, so they are sometimes known as tubular miniature light bulbs. These miniature light bulbs are small enough to fit into tight spaces and don't draw a lot of energy.