Mark Scrivener of Mark's Custom Aircraft Parts delivered the first batch of the towplane release assembly designed by Tom Martin back in 2004. I have 20 for sale priced at $29.95 + $3.00 shipping and handling. The release comes with 4 6-32 3/4" socket cap screws, washers and nylon lock washers. Mark mills the body of the release out of 6061 aluminum alloy. Click here to order.