Hello About the PPM 1 I don t understand Cyrillic alphabet that much so I could recognize that Thanks for that You are welcome dear SuperTank17 About BMP 1SM Since it s Czech variant than shouldn t it be called BVP 1SM And are you sure it s a Czech variant and not a Czechoslovak variant I will check this tonight using additional sources And inform you of course The problem is that book by Malyshev has the chapter Czechoslovakia Czechia Slovakia and it is not very easy to answer on your question exactly because of this I thought it was Czech variant I also would like to know what do you mean by driving wheels since you already told me that they aren t roadwheels Than what are they Return rollers If I remember correct there are four main types of wheels of AFVs roadwheels return rollers idler wheels and driving wheels drive sprockets I mean driving wheels the most forward wheels of BMP 1 one on each side gear wheels Perhaps drive sprockets are more common name for them Regards Vladimir