A:Answer "KL" indicates "LHR" (hence the "L"). LHR is a limiter than slows down crypto currency mining of specifically Ethereum.
"KB" indicates a new product sold by Bestbuy, and in this case predates LHR being implemented.
"KR" indicates a new product sold by somewhere else, and also predates LHR being implemented.
"RX" indicates a bstock/warranty replacement/manufacturer-refurbished product sold or shipped by EVGA directly, and also predates LHR being implemented.
"RL" indicates a bstock/warranty replacement/manufacturer-refurbished product sold or shipped by EVGA directly, and has the LHR component.
These are basically all of the EVGA SKU suffixes currently on the market.