What does channel 7 and 8 on a 6-slot 500 series rack do?

API 5008B - 8 Slot API 500 series Lunchbox · 8 Slots with 250 mA of power per slot · Full compatibility with API 500 Series and VPR-approved modules · DB25

There's a fairly large price range for 500-series chassis According to Sweetwater's site, the most expensive chassis is the most

88 fortune slot machine It offers 8 Slots, Full compatibility with API 500 Series and VPR approved modules, DB25 connectivity, Phantom Power, Optional Rack Ears, Toggle switches,

8pg slot This chassis accommodates 500 Series modules of all shapes and sizes, including double-wide modules and power-starved Class A and vacuum tube-fueled designs