Ok here is the link to the Spring Loaded Landing Gear

http://xgearheli.com/gallery1.htm

$34 plus ship[ping from Australia, that is for Trex450 gear, they are made for 450 electric through 90 size gas helis.
Seems a little much for a smaller heli like the Trex 450 or Belt CP and similar. Just buy Super Skids, cheaper, less complicated, lighter, very durable and have a spring like action with a heavy landing.

450 size Super Skids
http://www.ushobbysupply.com/product...dc96be26704042
R[8D]N Sr