Endless straps with
cam buckles are an excellent tightening system because pulling the strap rather than ratcheting like with a ratchet strap lessens the chance of damaging cargo. Endless straps work by wrapping the strap around the cargo then feeding the webbing back through the assembly. If you need more tensioning power, try a rachet strap such as
1" x 13' endless ratchet straps and
1" x 20' endless ratchet straps.
California Residents: WARNING