These WD12X10136 (the wheels) are lower dishwasher rack rollers, Gray in color.  WD12X10136 measure 1-3/4" diameter x 3/4" thick.  Replacement for numbers AP3676228, PS958949, WD12X10107 and WD12X10126   These WD12X10277 (the Axles) are plastic stud's that clips to the rack & the roller snaps into it.  WD12X10277 are Grey in Color.  WD12X10277 are made of Plastic.  WD12X10277 replaces numbers AP4355749 and PS2337855.   WD1210136 & WD12X1027 fits specific General Electric manufactured dishwasher models including GE, Hotpoint, RCA.