Gemstone is proud that is is dual listed by both Home Innovation Lab (Formerly NAHB) and UL (Underwriters Laboratories) in the USA. Gemstone is also listed in CANADA under UL-C. Both Home Innovation Lab and UL are listed under HUD UM Bulletin NO. 73a &B45.5/IAPMO Z124 Harmonized Standard for kitchen sinks and lavatory bowls.