2pcs 500mm Tr8X8 Lead Screw with T8 Brass Nut for 3D Printer Machine Z Axis(Acme Thread, 2mm Pitch, 4 Start, 8mm Lead)

I bought these for my custom Ender extender for a 550 build height and they are literally the exact same as what comes on the Ender 3 Pro and V2 just really long. The original Ender extender was not tall enough for me so I decided to go with this and the 600 mm 2040 V slots and I couldn't be more happy with it as you can see in the picture how much taller and wider this is than my S1 to the left and V2 on the right

I used these to set up a dual Z on my Ender 3 Max and they worked great.

Good threading and just what I wanted.

Acme thread on the screw fit nicely in the nut. I used this with a stepper motor to drive a trombone capacitor in and out.

It'll work magnificently. Only caveat being that it's too long for an Ender 5 plus.I brought the couplings as low as they'll go, and it still sticks out too much.About 20 mm too high. Which ends up colliding with the carriage or hotend.Trust me, one of two things will give, your carriage or these leadscrews.For me, it eventually caused a misalignment of the carriage, and bending of the leadscrew.Which in turn caused the issue of layers being squished or underdeveloped.So if you decide to buy a pair, make sure to cut them down to either 470mm or 480mm.I used a cut off wheel, and then ground them both down evenly.Alternatively, I could have used a metal cutting blade on a low speed miter and prevented the bluing or heating of the stainless steel and got a cleaner cut.

I couldn't believe these were exactly like they were listed. I was afraid I would accidentally get a standard-type rod, but this was exactly as stated.They came packed nicely in a cardboard box, straight as could be.

The nuts have .005” of backlash

This worked great for my genmitsu 3018 upgraded to 3040