According to Wikipedia the pong lang (Thai: โปงลาง) is a log xylophone from the Isan region of northeast Thailand.
The pong lang has 12 wooden bars that, with a strong rope, are tied together in a row at each end. The instrument can be played solo or in an ensemble. The pong lang is used for all kinds of occasions, especially for festivals and ceremonies.
The instrument is generally played by two players, who each use two hardwood sticks. Its shape is like a xylophone consisting of 15 wooden bars strung together with a strong rope at each end. The lower pitch end is attached to a post or part of a tree and other is hooked to the player’s toe or another material. The two performers sit on either side, one playing the melody, the other playing drone accompaniment. The pong lang has no standard size.
The reason I am telling you all this is because a reader of mine needs to hire one for an upcoming ceremony. It would preferable need to be in the Ubon/Sisaket area. If any of you locals out there know where one might be available then please send me a message.