Teaboy
So, they are:
m4 × 10 a4 But, with a low profile head. The standard m4 × 10 pz head will be too big.
I will gladly send you these 7 (1 for next time!!) which are m4 × 10 a2 tt20 head.
Green is original
Green is original
Which are as close to the original profile i have.
Note tt20 is security with the pin and different from t20!!
Screwdriver bit Easily available from Screwfix if you do not have and as part of a DeWalt bit set usually.
Id guess you damaged the original by not “shock loading ” with a positive flick.
Send me your address to my email in my signature and will post out to you
This is a great set to get you going
DEWALT DT7969-QZ, 32 Piece XR Professional Magnetic Screwdriver Bit Accessory Set, Yellow https://amzn.eu/d/aaVT7JF