diff --git a/Hardware_developement/4-HV/4-Push-pull/Readme.txt b/Hardware_developement/4-HV/4-Push-pull/Readme.txt
index 1affe07..11bcaeb 100644
--- a/Hardware_developement/4-HV/4-Push-pull/Readme.txt
+++ b/Hardware_developement/4-HV/4-Push-pull/Readme.txt
@@ -2,3 +2,21 @@ The core of the push-pull excitation is a pair of switching transistors and a pa
 
 The schematic is available in Fig. 17 in the following document
 https://o-esd.etf.bg.ac.rs/forgejo/dragan.olcan/O-ESD/raw/branch/main/Documents/O-ESD-02.pdf
+
+Currently considered transistors are
+
+TIP122
+https://eu.mouser.com/ProductDetail/STMicroelectronics/TIP122?qs=ljbEvF4DwOPuWPwhe20bIQ%3D%3D
+
+MOSFET N-CH 200V 18A TO220AB
+https://www.digikey.com/en/products/detail/infineon-technologies/IRF640NPBF/811884
+
+MJE15030G NPN 150 V 8 A 30MHz 50 W 
+https://www.digikey.com/en/products/detail/onsemi/MJE15030G/919491
+
+N MOSFET, 800 V, 11 A, 0.35 ohm, TO-247
+https://uk.farnell.com/stmicroelectronics/stw11nm80/mosfet-n-ch-800v-11a-to-247/dp/1752196
+
+MOSFET N-CH 200V 9.9A TO220-3
+https://www.digikey.com/en/products/detail/vishay-siliconix/IRLI640GPBF/812191
+