Heinrichs Weikamp OSTC 2 TR

Name: Heinrichs Weikamp OSTC 2 TR
Brand: Heinrichs Weikamp

The OSTC 2 with wireless transmitter support for air integration.

Open BLE sync (libdivecomputer)

Syncs wirelessly with third-party apps (Subsurface, Currents, etc.), not just the manufacturer app.

Released	2018
Max depth rating	120m
Algorithm	Bühlmann ZHL-16C with optional gradient factors
Air integration	wireless
Wireless	—
Display	Full-color LCD IPS-TFT
Battery	rechargeable
Digital compass	—
Gas types	air, nitrox, trimix
Gas switches	6
CCR capable	Yes

"Gas switches" is how many different mixes this computer can be programmed to switch between mid-dive, mostly relevant for technical/staged-decompression diving. It doesn't tell you which gas types (air, nitrox, trimix) are supported. See Gas types and the product description above for that.

Pros

Adds gas-integration transmitter support on top of the standard OSTC 2 feature set
Up to 60 hours of runtime in dive mode
Open-source firmware and Bluetooth data transfer

Cons

Could not confirm current pricing, the "TR" listing no longer appears as a separate SKU on Heinrichs Weikamp's current storefront (hwdiving.com), which now sells the OSTC 2 as a single model with a firmware choice
Niche brand with a smaller dive-shop support network than the majors
No built-in digital compass

The OSTC 2 TR is the transmitter-ready variant of the OSTC 2, adding wireless gas integration to the same open-source, 6-gas trimix platform. Product photo shown is the base OSTC 2 housing, which the TR variant shares. Note: the manufacturer’s current online store no longer lists “OSTC 2 TR” as a distinct purchasable product. It’s unclear whether the TR variant has been discontinued, folded into the base OSTC 2’s feature set, or simply moved to a different sales channel.