If not then you can get a lamp dimmer from Lowes or Home Depot for about 10$
this works SO well. I got the dimmers last week for my tanks and while it took a few days of working with getting the perfect spot, im now at a perfect 90.0 =]
(slight variance during the heating and cooling of the day)
0.1 normals, 1.0 spider, 0.1 pastel, 7.5 crested geckos, 1.0 leopard gecko, two dogs, three cats, birds, rats, mice and an old lady (shes the viscous one!)