The 500 Series Thread - Equipment - lines -

2-slot, 6-slot, and 10-slot configurations Later, API would series specification standards to ensure compatibility with API 500-series rack systems

API Rack Ears Lindell Audio PEQ-501a 500 Series Retro 2-band Program Equalizer $ Lindell Audio API - 5008B 8 Slot Lunch Box

2 slice long slot toaster Bento 2 The Fredenstein Bento 2 is a high performance two module carrier for Fredenstein Series 600 modules or API-500 compatible plug-in cards

20 super hot slot free Heritage Audio OST-10 10-Slot 500 Series Rack $1, Add to wishlist Heritage Audio OST-8 ADAT 500 Series Rack $1, 1; 2 Latest