I never liked the OEM DT on my NarCa from elsewhere (about the same atty FAIK), so I used this: SKU 4228400

Looks pretty nice. The shadows are misleading here, it's the exact diameter.

NarSqueeze FTW!

There are other colors, but this 'faux bone' look is sweet, IMO.
Bonus: they are super-comfy, good AF, fit nearly everything 510 size and have two o-rings.