[L-2]

https://www.midwayusa.com/s?userSearchQuery=glock+adjustable+rear+sight&userItemsPerPage=48

You might also try LPA sights (I've not tried them however).

I've used Glock's own adjustable rear sight which most folks wouldn't recommend, but they do work. I admit they're not what I'd call durable. You can just about push them into or out of the dovetail with your fingers.

I've got a Kensight on my G34Gen3. It does sit quite high off the slide and I went with a taller front sight ~0.330" to get to the mid-range of the rear adjustment. I probably could have gone a bit lower as there's a .315" version. As I recall, I was bottomed out using a stock .165" height front sight.

 

[L-2]

http://www.novaksights.com/Products.aspx?CAT=9454

Novak and DawsonPrecision both list three adjustable rear sight versions on its website. They both have good reputations for quality products. I've got a Novak adjustable rear sight on a 1911. It's only adjustable for elevation, but it's just what I needed. I've not personally tried DawsonPrecision products.

https://dawsonprecision.com/sights/glock-sights/glock-adjustable-rear-sights/

 

[ToddKS]

I have multiple sets of Dawson sights, both fixed and adjustable. All have been excellent. Dawson is a great company to deal with as well. Very helpful.

 

[Chordeiles]

Don't know if FO is your thing or not,but I put these Williams sights on my 20 and like them a lot.
https://williamsgunsight.com/produc...ock-pistol-sights/target-pistol-sights-glock/

 

[Boogieman]

It looks like I'll be going with a Novak adjustable rear. Mostly because it's closer to the MMC sights that I'm so used to. But I'll be using a Dawson fiber optic front sight because it is serrated while the Novak is plain.

 

[Berto]

Happy with my adj meprolites, I did like the MMC I had on a BHP clone.