Bell 10957 16W Arial Pro Downlight IP44 - Emergency (1 Year Battery Guarantee), CCT 1660lm. The Arial Pro LED Downlight is a sleek looking luminaire designed to replace cumbersome CFL fittings. With a 7 year guarantee across both the IP44 & IP65 range, the Arial Pro can be installed in a variety of applications with the confidence of knowing this product will stand the test of time.