Reading SANDRA's Spec Sheet in Plain English

By GETAUVE Editorial Team · Published October 26, 2026

Reading SANDRA's Spec Sheet in Plain English

Two devices list 7 inches. One means insertable length. The other means the whole body.

Spec sheets compress real differences into similar-looking numbers. Here are the five that matter on a dual-zone device, and the ones that only look useful.

The Short Answer

Read five lines: 7 inches overall, two independently controlled zones, 12 levels, under 45 dB, and roughly 90 minutes per two-hour charge. Those cover fit, control, sound, and runtime. The 45 dB figure matters most if you share a wall, and the runtime figure matters most if you don't want to charge weekly. Everything else is secondary.

Total Length Versus Insertable Length

Say you're standing in a store with two boxes and no tape measure. This is the most common source of disappointment in the category. A 7-inch overall length doesn't mean 7 inches of insertable length, and the difference is usually a handle or a motor housing.

For a dual-zone device, the split matters more than the total. One zone sits externally, one sits internally, and the distance between them is fixed by the body. That distance is what determines whether both zones land where they should.

So the useful question isn't "how long is it." It's "how far apart are the two zones." A device with a long body and closely spaced zones fits differently from one with a short body and widely spaced zones, even at the same overall length.

If you're comparing two spec sheets, that's the number to look for. If it isn't listed, the overall length is a weak substitute.

Decibels Per Zone

A single dB figure for a two-motor device is an average, and averages hide the interesting part.

Under 45 dB is the published number, and it's accurate for normal use. What it doesn't tell you is that two motors running together produce roughly 3 dB more than one, and that 3 dB is audible in a quiet room.

So the practical reading is: under 45 dB with both zones, quieter with one. If you share a wall, that's the sentence that matters, and it isn't on the box.

The other thing a dB figure can't tell you is vibration transfer. A quiet motor coupled to a wooden headboard is louder through the wall than a louder motor on a folded towel. The spec measures air noise.

What Twelve Levels Means

Twelve levels sounds like fine control, and it is. It also means the steps are small, which changes how you use the device.

On a five-level device, the jump from two to three is obvious. On a twelve-level device, the jump from six to seven is subtle, and subtle steps are harder to evaluate in the moment.

That's why anchors work better than counting. Pick three positions — low, middle, high — and read the rest of the range as fine adjustment between them.

Twelve levels across two zones is also a lot of combinations. The spec doesn't tell you that most people settle into a small subset within a week, which is true of almost every adjustable device and worth knowing before you pay for range you won't use.

Runtime and Charge Time Together

Runtime is only meaningful next to charge time, and the two are usually listed in different places.

SANDRA runs roughly 90 minutes and charges in about two hours. That ratio — 90 minutes of use for 120 minutes of charging — is typical for a dual-motor device, and it means a single session costs about a third of a charge.

What matters is the weekly math. At three sessions a week at fifteen minutes each, you're using 45 minutes weekly, so a full charge covers two weeks. In practice, a weekly top-up is more than enough.

The number to be skeptical of is a runtime quoted without a level. Higher levels draw more current, so a 90-minute figure at mid-level might be 60 at the top and 120 at the bottom.

Specs That Tell You to Wait

Some numbers are a reason to hold off rather than a reason to buy.

A length that's longer than your comfortable reach is one. The downside is that reach is not a spec, so you're estimating rather than measuring. A dual-zone body with fixed spacing that doesn't match your anatomy is another, and no amount of level adjustment compensates for a fit problem.

A noise figure close to your tolerance is the third. Under 45 dB is quiet in absolute terms, but if you share a thin wall with a light sleeper, "quiet" and "quiet enough" are different claims.

And a runtime that barely covers one session is a warning about battery age, not a specification. A device that lists 90 minutes and delivers 45 is an aging device, and the spec sheet won't update to tell you.

When the Numbers Aren't the Question

If you already know the shape you want, the spec sheet is a confirmation rather than a decision tool, and skip the comparison entirely. If your main concern is how it feels in the hand, no number answers that, and a return policy is worth more than a spreadsheet. And if you're choosing between two devices with nearly identical specs, the differences that matter won't be on either sheet.

Sources

• International Electrotechnical Commission — IP code definitions for ingress protection.
• National Institute on Deafness and Other Communication Disorders — reference sound levels and decibel scaling.
• Consumer Product Safety Commission — guidance on lithium-ion battery charging.

This is general education about reading specifications, not medical advice. Claims that sound like health claims should be verified with the manufacturer.