On Thursday, August 27, 2020 at 4:15:23 AM UTC+10, K8 wrote:
Mine are lead. They are stamped 2.45 KG. They are 5.5 cm x 2.8 cm x 14.5 cm. The mounting hole in the center is approximately 1.7 cm in diameter and the hole is threaded. I hope that helps.

Doug
Hi Doug, Many thanks for the info - just what I needed.
Happy Soaring, Geoff.