Read the material for each component
A bridge assembly can contain different materials in its body, saddles, posts and screws. Finish is another specification. Do not infer the base metal from a chrome or gold appearance.
For example, the linked aluminium wraparound lists an aluminium-alloy body with brass posts and bushings. The other wraparound lists an all-brass body. Both list 52.5 mm string spacing, 81 mm post spacing and 5/16-24 imperial post threads. Those are concrete comparison points, though they still need to match your instrument.
Avoid a universal material-to-tone formula
The catalogue identifies construction and dimensions; it does not supply controlled sound measurements for these bridges. It cannot substantiate a fixed increase in sustain, a faster attack by a stated number of milliseconds or a rule that heavier always sounds warmer.
Choose based on verified fit, adjustment needs, finish and your reason for replacing the current part. Treat descriptions of warmth, brightness or resonance as impressions to evaluate on your own setup.
Make the comparison useful
Before changing hardware, record a short clean passage and a few sustained notes. Note the string type and age, action, tuning, pickup height and signal-chain settings. After fitting and checking the setup, repeat the recording under the same conditions.
Compare recordings at similar playback volume.
Include the chords and playing dynamics you actually use.
Check intonation, adjustment range and playing comfort alongside sound.
If several parts or the strings change together, describe the result as a whole setup change.
