Direct Attach Cable (DAC) for QSFP+

Hello,

Does anybody know if Fortinet supports any active DAC QSFP+ to QSFP+ cable? In the pricelist I only found a quad cable QSFP+ to 4xSFP+, but not a QSFP+ to QSFP+. I need to connect two FSWs over 40G and if I use the QSFP+ transceivers the price goes too high. Our competitor (HP) has proposed DACs at a very competitive price that kicks us out of the project. Has anybody used DACs to connect FSWs at 40G? Which vendor?

Thanks

Andreas