TR438 valves are a relatively long straight valve used in rims with relatively large valve holes, such as those on all NAMI models including all current Burn-e, Klima and Blast models.
Consensus on TR438 specification appears to be 8.8mm valve hole size, perfect for NAMI (Hamaton, although variances are noticed such as 8.89mm and 11.3mm). TR438 measure up on callipers as having a 12.3mm seat, which is larger than:
The more common Straight Valve which has an 11mm seat which is typically suitable for 8.8-9.5mm valve hole, although this known to be unsuitable for NAMI motors (slow leaks).
The 90 degree PVR50 type has 12mm seat for 9.5-10mm valve hole.
It is recommended to renew valves when tyres are changed.
Available as Genuine NAMI Factory Spare, or alternative aftermarket which is not a NAMI Factory spare but likely of same production quality. TR438 type is actually used in Automotive industry mostly by Mercedes Benz.
41mm length. This is lengthy, so they do protrude, often PVR50 type is fitted as these are slightly more "recessed".
Notes
Product images 4 to 6 show the contrast of the TR438 (wider, longer) vs the more common eScooter Straight Valve.
Note: older Burn-e model 35Ah (Non-2) and earlier versions of the 32Ah (2 Max) and 28Ah (2 non-Max) were initially factory fitted with PVR50 type (easy to identify as being a 90 degree valve). Both TR438 and PVR50 are suitable for NAMI motors, much has to do with preference for straight or bent 90 degree.
A random sample measure with callipers of holes in motors (Burn-e and NAMI) measures around 8.8-9.5mm.
TR438 is also a good option for most makes/models that have PVR50 valves, such as Wolf Warrior series.