What size utility knife blades will fit in the RKT series utility knife?

There are currently a few different size utility knife blades available on the market for replacements. The RKT series of utility knives use a 2-3/8″ blades with two slots at the top of the blade. Blades with 3 slots or of a different length will not properly fit in the knife and can cause it to jam and not be able to retract.