When working in the derrick, a Derrickman used a “wrap around/tie-off adapter” for his fall protection anchor point. The adapter was about 2’ long and made of 3” nylon webbing. The particular one involved in the near miss had a “loop” (like a regular sling) on one end, and a “metal D-ring” on the other. The tie-off adapter is wrapped around a secure structure (pipe, etc)… the D-ring end is then slipped through the loop end. The user’s lanyard is then attached to the metal D-ring. The derrick man had tied off and was leaning out from his platform when the tie-off adaptor “broke”. He caught himself on the pipe and did not fall.