Their is an international numbering system for metric bearings:
First number/s identify the type of bearing. 6 is single row ball bearing, 7 is single row angular contact, 1 is double row ball self aligning, 22 is double row spherical roller self aligning, etc
Second number is the "series", eg 3 is heavy, 2 is normal, 0 is light, 9 is extra light, and I think there is even an 8 extra extra light series.
The last two numbers donate bore size, 00 is 10 mm, 01 is 12 mm, 03 is 15 mm, 04 is 17 mm and thereafter the bore is 5 mm x the number. In an "-08" bearing the bore is 40 mm. Below 10 mm, there is only one number, so 629 is a 9 mm bore, 608 is 8 mm bore and so on.
Then there are suffixes, Z and ZZ mean metal shields, RS and 2RS (and other manufacturer dependant suffixes for specific types of seal) means rubber seals, NR means a circlip groove and ring, C2 means less internal clearance, C3 means more internal clearance.
So the bearings in this case are extra light series, single row ball bearing, 25 mm bore, 42 mm OD and 9 mm wide, with one and two rubber seals respectively. Should be available from any bearing company, might not be available off the shelf as this series is not usually stocked everywhere.