T-Type pulley wheels are a slightly weird beast because the upper and lower pulleys are different sizes (14T upper, 16T lower) and the cage geometry is specific to the flipped-parallelogram design. Standard Eagle pulleys
will not fit. That narrows the field, but there are a few options worth knowing:
Genuine SRAM
SRAM sell the X0/XX T-Type Pulley Kit as a service part — black only from the factory, but the X0 version has a slightly nicer finish than the GX one. Functional rather than fashionable.
Garbaruk
The Polish lot do a proper T-Type compatible pulley set in CNC'd aluminium with sealed bearings, available in
red, blue, gold, purple, black and silver. Probably the best-known aftermarket option for coloured T-Type pulleys. Around £55–70 a set depending on retailer.
KCNC
Make a T-Type compatible jockey wheel set in several anodised colours (red, blue, gold, black). Cheaper than Garbaruk, ceramic bearing options available. Quality is decent if not quite Garbaruk-level.
Kogel / CeramicSpeed
Both do T-Type oversized pulley kits aimed at the watt-saving crowd. CeramicSpeed's OSPW for Transmission exists but it's eye-wateringly expensive (£400+) and mostly black/gold. Probably overkill for an eMTB where you've got 600–850W of motor laughing at drivetrain friction.
AliExpress / generic
There are unbranded T-Type pulley sets floating about for £20–30 in every colour under the sun. Bearing quality is a lottery — some are fine, some are gritty out of the box.
@Astro66 has had luck with the Aliexpress S1000 derailleur, so the ecosystem isn't all junk, but pulleys are a wear part and I'd lean toward Garbaruk or KCNC for peace of mind.
One caveat
T-Type relies on very precise chain gap and pulley alignment — it's part of why shifting under load works so well.
@Blownoutrides found even a SRAM XX derailleur a few mm out of spec caused broken cassette teeth and chewed chains. Cheap pulleys with sloppy tolerances or wrong tooth profiles can absolutely upset that, so don't go too far down the bargain-bin route.
My pick:
Garbaruk for colour choice and proven quality.
What bike and colour scheme are you working with? Happy to narrow it down further.