【NEWS】四次元背包補貨完成，優惠仍在，現貨不用等！(Click Here to Buy)

▲ What is "4D Expansion"? Let us demonstrate it live!

4D Expansion Backpack

隨心切換，一秒擴充，
運動 / 商務 / 通勤全制霸！

可裝籃球 / 可裝全罩 / 筆電防護層

找不到各種場合都好用的後背包？

For weekday work, you need a sleek laptop & tablet bag;
For sports & leisure, you need a bag for gear, bottles, and clothes;
For international travel, you need a high-capacity, multi-layer, waterproof bag...

籃球、球鞋、水壺放哪裡？

上班這樣揹不專業、不體面

旅行東西這麼雜怎麼分類收？

4D Expansion Backpack

運動打球 x 商務通勤 x 出國旅行

\ 一次滿足！ /

【空間革命】

極速擴充四次元口袋

空間折疊術｜瞬間增加20L的空間魔法

未展開時，俐落方正 > 展開時，大肚量怪獸！

Expand from 36L to 56L in 1 second!
Equipped with our exclusive "4D External Mesh Net System",
hidden when unused, expanding space by 70% in an instant!
🏀 Sports & Leisure: Fit basketballs and sports gear effortlessly
🍲 Daily Shopping: Even fits a 10-person Tatung electric cooker
⛑️ Daily Commute: Fits a full-face motorcycle helmet with ease
🧥 Travel: Pack heavy coats hands-free

【收納革命】

15+口袋分類分層收納系統

條理分明收納｜J人歡呼、強迫症鬆口氣的整理收納術

雙中層設計，
將「工作」與「生活」完美分流

數位核心區

筆電層前後軟墊防護，
另增平板夾層，
提供頂級避震防護。

生活收納區

耳機、行動電源、滑鼠、筆記本、鑰匙、甚至是一支筆，都有專屬歸宿。

【舒適革命】

零重力背負系統

會呼吸的背墊｜20mm 超厚 3D 氣墊

Back area uses high-spec 20mm honeycomb air cushions for soft back support.
Features 3D ventilation channels to create airflow and dissipate heat efficiently.

負重若輕｜S 型減壓透氣背帶

Ergonomically designed S-curve shoulder straps
fit shoulder contours perfectly to prevent pressure concentration.

Decompression foam evenly distributes bag weight across chest and back;
Full breathable mesh on body contact areas ensures quick moisture-wicking and heat release.

動靜皆宜｜可拆卸式穩定胸扣

Designed with a flexible, detachable chest strap system.
Wearing formal clothes and want a clean look? Simply detach the chest strap!

運動模式 (裝上)

當背包重量不輕又需要
長距離走動，扣上胸扣，
背帶不易滑脫、
分散背腰受力。

商務模式 (拆下)

正裝場合，
可將胸扣完全拆卸收納，保持外觀極致簡約。

運動 x 上班 x 旅行

\ 一包就夠！ /

運動員靈魂｜細節見真章

球這樣放

籃球可以放，其他甚麼球都可以放！

球拍、球棒這樣放

貼心球拍固定環，不東倒西歪

可拆式保冷袋/鞋袋

獨立收納袋，自由切換更方便

保冷/溫飲料袋

鋁箔保溫層，可拆式行動小冰箱

球鞋獨立空間

可拆式獨立鞋袋，隔離異味與髒污

社畜小確幸 | 俐落通勤，帥氣賣肝

經典全黑，挺拔有型

皮革感厚實耐磨表布，除了耐用還很好看

肩帶隱形卡片夾

無需卸下背包，帥氣通關！

頂級防水

防水面料加全防水拉鍊，大雨也不怕！

安全反光條

夜間高反光，通勤夜衝保平安

社畜小確幸 | 俐落通勤，帥氣賣肝

行李箱把手扣帶

穩固不滑脫，帥氣拉著走

快取絨面口袋

機票護照一秒拿，不刮鏡片安心放

可擴充側袋

雙邊拉鍊擴充，1000ml胖胖瓶也放得下！

Crosign Sincerely Recommends:

If you love backpacks and frequently switch between work and leisure modes,
or often carry helmets, basketballs, and large items,
or need a place to stash bulky jackets when taking them off,
then you MUST try this backpack!

Don't let capacity limit your imagination; don't let clutter slow your pace.
Get yours now and experience unprecedented expandable freedom.

舊版低價擴充包
vs.
新版四次元擴充包

	舊版低價擴充包	👑新版四次元擴充包
容量	30L	👑56L
內袋	5-9	👑15+
置物艙	單層	👑雙層
肩帶/背墊泡棉	<1cm	👑2cm
四次元擴充袋	小	👑大
可拆式胸扣	無	👑有
可拆式鞋袋/保冷袋	無	👑有
羽球拍固定環	無	👑有
快取絨面口袋	無	👑有
快取卡片夾	無	👑有

Similar-looking bags sold on some Taiwan e-commerce sites or Taobao cost around NT$700-800.
In the spirit of Crosign scientific testing, we bought and tested them all!

The difference is massive!
The 【4D Expansion Backpack】 clearly outperforms cheap alternatives in texture, volume, and functionality.
Especially in capacity, cheap front mesh bags barely fit a single basketball,
and cannot fit full-face or larger 3/4 helmets at all.
Fabrics, waterproof zippers, pocket layers, and detachable pouch designs are completely superior.

If you truly want a versatile, durable, and reliable backpack,
we wholeheartedly recommend the 【4D Expansion Backpack】.
Received a 96% satisfaction rate from early user feedback surveys!
We are confident you'll be amazed by its high quality and craftsmanship upon delivery,
and continuously impressed by its practical design in daily use.