The ComBow has an unique slingshot that employs a pulley system in order to extend the draw length.Several different versions exist, some of them were sold by Beeman in the 70ies. Beeman stopped slingshot production, but Robert Blair, the inventor of the ComBow, continues to sell newer versions.
The ComBow is probably the most sophisticated slingshot on today's market. Its pulleys increase power consisderably - read the Power section for more about this topic. With proper pouch assembly, the ComBow can be used to shoot special arrows, and it is one of the few arrow-shooters that really works. If you want to purchase a ComBow, contact Robert Blair at firstname.lastname@example.org or by mail:
P.O. Box 5474
And be sure to check out their webpage: http://www.combowslingguy.com