Description
The training session this pair is designed around
The TRAUSI i27 is a sealed in-ear true wireless earbud with a soft ear hook wrapped around each side. The hook does the retention work so the ear tip does not have to, which is why this shape keeps reappearing in gym and running products: a bud held only by canal friction works loose the moment you sweat, while a hooked bud stays put through burpees and hill repeats.
TRAUSI quotes 7 grams per side, which is light for a hooked design, and the earbuds ship with three sizes of silicone tip. The buyer served here wants secure retention, an immersion grade water rating and a case that lasts a week between charges, and is not expecting active noise cancellation or a documented codec. Both of those are absent, and the listing does not pretend otherwise.
Connection: profiles are published, codecs are not
This listing does something unusual and worth explaining, because it is easy to mistake for more information than it is. TRAUSI lists support for HSP, HFP, A2DP and AVRCP. Those are Bluetooth profiles, not codecs. HSP and HFP handle headset and hands free calling. A2DP is the profile that carries stereo music. AVRCP is the remote control profile that lets the buttons skip tracks. Every set of Bluetooth earbuds on the market supports all four, so the list confirms the product works normally and tells you nothing about audio quality.
What would tell you something is the codec, and no codec is named anywhere on the page. A2DP mandates SBC, so SBC is present by definition. There is no published evidence of AAC, which is the codec Apple devices use, and none of aptX or LDAC, both of which require the phone and the earbuds to support the same one. The bullets promise “crystal-clear sound quality” and “rich, detailed audio,” which are adjectives. Nothing here supports a high resolution description, and the “low-latency audio” claim comes with no figure in milliseconds to check it against.
TRAUSI lists Bluetooth 5.4 with dual channel transmission and automatic reconnection when the buds leave the case. Version 5.4 improves connection stability and power behavior. It does not raise sound quality by itself. Multipoint pairing to two devices at once is not mentioned, so assume it is absent.
Battery: 6 hours, 54 hours, and a case that looks small for the claim
TRAUSI publishes the split, which is the right way to do it: up to 6 hours of playtime from the earbuds on a single charge, extended to 54 hours with the charging case. A 10 minute quick charge is quoted as returning 2 hours of playback, and the case itself fills in about 1.5 hours over Type-C. An LED percentage display shows the remaining charge.
Six hours is the number that matters day to day, and it is on the modest side for a hooked sports design, where the housing has room for a larger cell than a stemless bud does. The 54 hour figure is the total across roughly eight returns to the case.
One thing does not add up cleanly. The case is listed at 400mAh, which is small for a claimed 48 additional hours of playback across two earbuds. Cases in this bracket delivering totals near 50 hours typically carry 500 to 600mAh. The arithmetic is not impossible, but it is optimistic, and this is the sort of headline figure worth treating as a ceiling rather than a plan. Quoted playtimes across the whole category are measured at moderate volume in any case.
Fit, IPX7 and the specification fields that disagree
Three sizes of silicone ear tip are included, small, medium and large. On a sealed earbud that is the specification that decides how much bass you actually hear, because a leaking seal thins the low end no matter what the driver is capable of. The ear hook is described as soft and ultra light, and TRAUSI quotes 7 grams per side.
The specification table then lists item weight as 1 gram, restated as 0.035 ounces. A one gram earbud containing a battery, a radio and a driver is not physically possible, so the 7 gram bullet is the credible number. The same table claims the product requires “1 A batteries,” which is another impossible entry for a sealed rechargeable device.
The shape fields contradict each other too. Ear Placement reads In Ear while Form Factor reads Over Ear, and Amazon’s own ranking places the i27 both 135th in over ear headphones and 370th in earbud and in-ear headphones. It is an in-ear bud with an over ear hook, and the confusion is in the data rather than the product. More usefully, the included components list mentions a “Wireless Charging Case” while the battery bullet describes only Type-C charging. If charging the case on a Qi pad matters to you, confirm it before buying, because the listing supports it in exactly one place and contradicts it in another.
The water rating is IPX7 in both the title and the bullets, with the specification field falling back to the bare word “Waterproof.” IPX7 is a real immersion rating, tested in fresh water at roughly one meter for about thirty minutes, so sweat, rain and splashes are comfortably inside it. It does not cover seawater or high pressure water such as a shower jet, and IP protection degrades as seals and port covers age.
Use cases, awareness and what else to consider
TRAUSI lists cycling among the recommended uses. That is the one recommendation to ignore. These seal the ear canal, and a sealed bud removes exactly the ambient cues that tell you a vehicle is approaching. Gym, treadmill and trail use are reasonable. Roads are not, and if your route involves traffic the honest alternative is a design that leaves the canal open, which is what our open ear headphone reviews cover.
The listing gives the age range as adult and teen and publishes no volume limit anywhere, so there is no cap on output to rely on. Amazon lists the i27 as ranked 2,628th in Electronics, with a 4.6 star average across roughly 893 ratings, and it first appeared in January 2025. Within the same hooked sports format, the Catitru i25 wireless earbuds and the occiam T9 sports earbuds are direct competitors at a similar level, while the JBL Endurance Peak 3 and the JLab Go Sport Plus come from brands with longer records and fuller published specifications. The wider format sits in our earbud headphone reviews.
Buy it, or skip it
Buy the i27 if you want hooked retention for hard training, three tip sizes, an immersion grade IPX7 rating, a fast charge that returns two hours in ten minutes and a percentage readout on the case. Skip it if six hours per charge is not enough for your sessions, if you need a named codec or a real latency figure, or if wireless case charging is a requirement, because the listing states it once and contradicts it elsewhere.
