The Karaweik (both, K1 and K2) has an octagonal base, a tuft with three ends (here worn) and the bird mark. Important is the octagonal base to distinguish Karaweik from Hintha.

Your Karaweik 2 is heavily worn, with two rows of neck feathers.

My Karaweik 1 is a 10 tical weight with three rows of neck feathers, also with wear and tear, leaving a beautiful natural patina.



Another Karaweik 1 (10 tical):



And finally a Karaweik 2 (10 tical, 150 g), similar to your 20 tical weight:

Again not K2 but K1 20 tical (L-R: 307, 308, 316, 319 grams).
Usually they are well worn, but all the K1 weights show the bird mark as K2 weights also do. On K1 we still see the high, pointed beak of the fowl instead the flat beak of a duck on Karaweik 2.
The frieze of notches on the upper rim of the base, typical for Hintha 3 and Karaweik 1 weights of the Konbaung period (here well visible), disappear completely on Karaweik 2 forms.

Here we have a group of seven K1 10 tical weights in different conditions, but partly great natural patina and mostly with bird mark (L-R: 140, 147, 150, 158, 157, 159, 156 grams).

Here we have The Karaweik 2 weight, 20 tical (320 grams). A quite rare weight in excellent condition. Illustrated in Arts of Asia, Summer Issue 2021, Shan Beauties, fig. 32. Big bird mark!