Alkaline (LR)
Fine for calculators, toys, and devices that are used on and off.
Cheaper; voltage drops more as the battery ages.
Silver oxide (SR)
Steadier voltage — better for watches and precise instruments of the same size.
If the maker specifies SR, do not switch to LR just to save money.
Same size pairs
LR44 / SR44 is the classic example. Our code checker marks these as same size, different type.