Gunnebo 5/16" GBK Self-Closing Safety Hook - Grade 100Gunnebo GBK Grade 100 Self Closing Safety Hook The Gunnebo GrabiQ GBK Grade 100 Self Closing Safety Hook is engineered for professional lifting and rigging applications where safety, durability, and ease of use are essential. Designed for chain sling assemblies and other lifting systems, this heavy duty hook features a spring loaded self closing latch that helps keep loads securely engaged throughout the lift, even when conditions change or the load