>Anyone have any experience using the various endcaps and light holders? > I use the German ones sold by Champion Lighting and various pet supply houses. The are well made and I have not had any problems with then at all. I would recommend then to any one. Champion description: ENDCAPS $12.95 per pair T-12 or T-8 Waterproof - U.L. approved for all applications Note: The T-12 & T-8 sizes a separate endcaps and not interchangeable Champion Lighting 1-800-673-7822