I needed lights on my back stairs.  They were pitch dark at night.  I had a motion detector light at the top of the stairs but it did not light them.  These LED step lights do the job.  My husband a diy’er installed them.  They are AC not ACDC.  Do not need a transformer.  The picture shows everything he he used except 16 gage electrical wire.  Not difficult for an experienced person. The dark area on the stairs has no lights.  We will be buying another set unless we can get them individually. He also installed a photocell switch to turn lights on at dusk automatically and off at dawn.  Otherwise light will day on until you manually turn them off.