The phrase "a device that attaches" is correct and usable in written English.
You can use it when describing a device that connects or fastens to something else.
Example: "The new gadget is a device that attaches easily to your smartphone for enhanced functionality."
Alternatives: "an apparatus that connects" or "a tool that fastens".
A device that attaches sensors to your fingers and hands can track movements in high detail.
Sony recently introduced the Bravia Internet Video Link, a device that attaches to the back of its popular line of TVs and delivers high-definition online programming.
Graviky Labs created a device that attaches to vehicle exhaust pipes and diesel generator chimneys, capturing the particulate pollution they emit without affecting vehicle or engine performance.
He suggested that the easiest way to do it would be to use a forestry cutter, a device that attaches to a small vehicle and can be driven through an area to remove brush and debris.
Cheok's submission was one of the four finalists It is for a device that uses electric stimulation of the taste buds, coupled with a chemically produced scent emitted from a device that attaches to a mobile phone, to reproduce the flavours of any food or dish.
Albatrosses and other marine birds swoop on the bait, get caught on the hooks, and are dragged under water.This can be avoided by attaching streamers to the fishing lines to scare the birds away; by unreeling the lines at night; by attaching weights to the lines so they sink faster; or by using a device that attaches the bait after the hook goes under water.
Last year, Palm Inc. and Supra Products, a company that makes electronic locks, introduced the eKEY, a devices that attaches to the Palm Vx to give a real estate agent access to a house (as well as access to market information through the device's wireless and cradle connections).
Soltrackr is a small device that attaches to a key fob or carabiner.
This is a small device that attaches to your phone either through a physical connection with a chip and signature device (£20) or Bluetooth for chip and pin (£99 for the unit), reads cards and takes payments for you so you don't lose sales by going cash-only.
ShowerSmart, a small device that attaches to non-electric mixer showers or bath/shower mixer taps.
Graviky's system starts with a cylindrical device that attaches to the exhaust systems of vehicles or diesel generators.
