Parametric Keychain

Hello,
For fun, you can easely customize this keychain:
Parameters are (refer to picture also):
// Description parameter
K_Length = 40; // Length of the straight part of the key ring
K_Width = 20; // Width of the keyring
K_Thickness = 4; // Thickness of the keyring
K_Radius = 6; // Front radius (set-up to 0 for a rectuganlar part
K_Hole = 3; // Diameter of the hole for the attachment
K_D_Hole = 2; // Distance of the hole to the edge
K_Rounded = 1.9; // radius for sharp edge
Sketch_Th