Took a while to receive but I knew that before ordering. For some reason these are one fin to large to fit the Wltoys 124019-124018 or 144001 correctly. Had the dremel off one fin to get it to fit tight against the motor. Still have to tuck it underneath the top chassis brace but the extra fin prevented it from fitting snug against motor and left about an 1/8” gap where the fin hit the top brace. Ordered a couple of the heatsinks listed for the Wltoys 124028 and they fit the 124018-124018 & 144001 perfect. Still have to tuck a little under top brace but is snug against chassis, top brace and tight against motor. How these “should” fit since there marked specifically for 144001/124019
works very good, price is great