P13.5s is a standard lamp base, with 13.50mm diameter and length range from 25.20 to 30.00mm.

They are assembling with a high pressure xenon bulb, which offer a much increased light output and greater efficiency when compared to standard types, should also provide all the light needed to quickly identify any threats hiding in dimly lit areas. As a result, they make enhanced substitute bulbs for applications such as cycle lamps, torches and security products. However, they are much brighter than standard bulbs, life is reduced to between 15 and 20 hours.

There are many bulbs in the range:
2.40V 0.75A 23lumen
2.40V 0.90A 33lumen
3.60V 0.75A 43lumen
3.60V 0.90A 60lumen
4.80V 0.70A 60lumen
4.80V 0.90A 82lumen
6.0V 0.90A 105lumen
7.20V 0.90A 125lumen