Why compare these options?
For a roughly 20L day-out load, compare Protium 20 at 1000g with AC Lite 21 SL at 830g: the latter lists 1L more capacity and 170g less empty weight. The SL fit option still needs its own strap and wearer-fit checks.
- Does a published increase from 20L to 21L change the capacity you need for your planned day load?
- How much does the 170g empty-weight difference matter once you add your own contents?
- What fit and strap information is missing before treating the SL option as appropriate for your body and clothing?
Rab Protium 20L Day Pack
Deuter AC Lite 21 SLManufacturer model photographs; pictured colour and size are not independently confirmed. No hands-on winner or rating is assigned.
| Field | Rab Protium 20L Day Pack | Deuter AC Lite 21 SL |
|---|---|---|
| Published empty weight | 1000 g | 830 g |
| Outside dimensions | 52 × 28 × 22 cm · Axis names not published | 48 × 30 × 24 cm · length / width / depth |
| Published capacity | 20 L | 21 L |
| Shoulder strap | Unknown | Unknown |
| Pockets / storage | Pocket layout and usable openings are unknown | Pocket layout and usable openings are unknown |
| Recorded price | USD 170.00 · Rab United States official selected variant offer | EUR 110.00 · Deuter /de-en/ (EUR) |
| Specification option | QAP-60-DPA-MLG | 4046051156880 / shale-graphite |
What changes between the published specifications
The published empty-weight values differ by 170 g. This compares manufacturer figures; accessory inclusion and weighing tolerance may differ.
Listed capacity: 20 L versus 21 L. Volume ratings do not establish a pocket opening or the shape of an object that can fit.
Outside dimensions stay in the order used by each manufacturer. Match labelled axes where supplied; unlabelled axes do not support a height-to-height claim.
With an illustrative 1 kg load, starting totals would be 2,000 g and 1,830 g before any accessories excluded from the published weights. This is arithmetic, not a comfort or packed-load test.
Questions these numbers cannot settle
- Will your phone and passport fit together with the bag fully closed?
- Can you reach the needed pocket while wearing the bag?
- Does the strap adjust comfortably over your clothing and body measurements?
- How does the particular material perform in your use?
Use the two fact sheets for model details, then check those questions with the actual bag or directly with its manufacturer.
Open the comparison toolOfficial sources
- Rab Protium 20L Day Pack ↗Checked 2026-10-17
- Deuter AC Lite 21 SL ↗Checked 2026-10-15