This tail wheel spring configuration is designed for 35 to 40% giant scale model R/C aircraft and is guaranteed to last forever! This unique design uses compression springs and cannot be overstretched unlike any other tail wheel spring available.  These compression springs provide ideal tail wheel response and ground handling by increasing resistance the more the system is pulled.  They also overcome the major weakness in the typical (until now) extension spring systems.  Extension spring systems lose resistance the more they are pulled which causes increasingly weak tail wheel action.  This also leads to spring fatigue eventually decreasing its strength and effectiveness.  The components used in this assembly are made of fine gauge stainless steel to eliminate the possibility of corrosion.  This product solves every single problem you've ever experienced with a tail wheel spring.