A T2 thread, also written T-2, has a diameter of 42mm and a thread pitch of 0.75mm. It is also sometimes written as M42x0.75.
The low pitch distinguishes it from other M42 threads.

ZWO
Camera ASI 2600 MC Pro Color
RRP:
$ 3,190.00
Our price:
$ 2,687.00
ready for shipping in 24
h

ZWO
Camera ASI 2600 MM Pro Mono
RRP:
$ 4,110.00
Our price:
$ 3,457.00
ready for shipping in 24
h

ZWO
Camera ASI 174 MM Mono
RRP:
$ 930.00
Our price:
$ 779.00
ready for shipping in 3-5
weeks

QHY
Camera 183C Color
$ 980.00
ready for shipping in 1-2
weeks

ZWO
Camera ASI 462 MM Mono
RRP:
$ 441.00
Our price:
$ 371.00
ready for shipping in 24
h

Starlight Xpress
Camera Trius PRO-674C Color
$ 2,530.00
ready for shipping in 1-2
weeks

Starlight Xpress
Camera Trius PRO-674 Mono
$ 2,530.00
ready for shipping in 1-2
weeks

Starlight Xpress
Camera Trius PRO-825 Mono
$ 1,870.00
ready for shipping in 24
h

Starlight Xpress
Camera Trius PRO-825C Color
$ 1,870.00
ready for shipping in 1-2
weeks

Starlight Xpress
Camera Trius PRO-694C Color
$ 3,170.00
ready for shipping in 24
h

Explore Scientific
Camera Deep Sky Astro 26MP
$ 1,830.00
ready for shipping in 1-2
weeks

QHY
Camera 183M Mono
$ 1,380.00
ready for shipping in 1-2
weeks

QHY
Camera 294M Pro Mono
$ 1,780.00
ready for shipping in 1-2
weeks

Starlight Xpress
Camera Trius PRO-825 Mono, Combi Set
RRP:
$ 2,740.00
Our price:
$ 2,520.00
ready for shipping in 1-2
weeks

QHY
Camera 163 cool Mono
$ 1,600.00
ready for shipping in 1-2
weeks