First there were the 41" bands, then the 20" bands. Due to demand Iron Woody has taken even another step to fill our customers demands. The 12" bands are designed for everything that the 20" bands were designed for. These 12" bands are also designed for rehabilitation needs. They offer great subtle stretch and just enough elasticity for fine motor movements. The Pair of Large12" bands offer the heaviest resistance of the 12" bands.