Can't remember this coin

Thailand baht

which of them is it, so many of them look alike!

Could be any number of them - you'll need to show the reverse and if possible weight, diameter and metal

Possibly on here:

https://en.numista.com/catalogue/index.mobile.php?r=5+baht&c=

5 satang maybe

measurement is 22 mm I believe

I think it is this one - Rama IX 50 Satang 1957

https://en.numista.com/catalogue/pieces5433.html

Y# 81 50 SATANG = 1/2 BAHT
Aluminum-Bronze Ruler: Bhumipol Adulyadej (Rama IX) Obv:
Smaller head, 3 medals on uniform Rev: Mantled arms Edge:
Reeded

Date               Mintage        F   VF    XF  Unc BU
BE2500 (1957) 439,874,000 — 0.10 0.15 0.25 —
Note: Minted without date change until 1987