One set of contacts had rubber granular skins and I believe the skins came with yellow and black colored skins...no paint. The other set in the Pre-Elite ring, contacts were covered in black conveyor belting and the painted line was sprayed on using dashboard style of paint, bought at a local auto parts store. The dashboard paint is more pliable and will not stiffen the rubber conveyor belting.
All tunnels were 24" with 4" pitch.
The Elite ring used Salty Dog Tunnel bags (I think) with Salty Dog water bladders in them. The Pre-Elite ring had Tunnelbags.com bags (Nancy Holmseth is no longer making them but there are many 'copy cats' available, a google search will help you) They too were using Salty Dog water bladders in them.
The placement of the tunnel bags on the tunnels were allowed (in the middle) because all bags had water in them...not sand or other hard unforgiving material. Water bags will give when the dog hits them, just like a tunnel might give a little when the dogs bank on them. As far as I know, if water bags are not used at a trial, all tunnel bags must only be placed at the ends of the tunnels. Two sets on each end is acceptable.
