This article is from the Hanggliding and Paragliding FAQ, by Joao Geada with numerous contributions by others.
It's attached to a release which has lines which pass around the
pilot and attach to the glider at the same point the pilot
attaches. The release is positioned in front of the pilot so he can
easily operate it. There is a weaklinkbetween the release and towline
to protect the glider from overloads.