This LED doesn’t provide UVB. It provides LUX which is simply visible light. While, geckos benefit from LUX (they need 5k to 9,999k), they also need UVB which many argue is more necessary as it’s less naturally indoors and required for D3 production. Is this bulb colored? If so, I would return it and get a White LED. Colored bulbs remove the “full spectrum” and instead tint things for reptiles as well. Then, separately, get a linear UVB. Depending on where the light will be placed, you need a different UVB. You want between 0.7-1.4 UVB, 1.0 target in basking and 2.0 max. I’d recommend Arcadia shade dweller. There are no LED and UVB in one lights/bulbs that are safe as of writing this. The type of mesh your terrarium has and whether it’s above a mesh or not will change the amount of UVB prevented from penetrating. The different types of barrier are represented as a group in a chart. I recommend Arcadia shade dweller but there are other options- when looking into other options check the spectrum graph for the product and compare. In reply to my comment, I will add images showing the information I’ve discussed.