Andrian Cheng

A 20 amp household circuit takes 12 AWG copper wire and a 15 amp circuit takes 14 AWG; in 12/2 the 12 is the gauge and the 2 is the number of insulated wires.

The Cat number names a cable's performance grade; Cat5e handles gigabit, Cat6a carries 10 Gbps over a full 100 meter run, and Cat6 only on short runs.

Level 1 charges an EV from a 120V outlet at about 5 miles of range per hour; Level 2 uses 240V, adds about 25 miles an hour and refills most cars overnight.

A lower AWG number means thicker wire; Southwire rates its 16 gauge cord at 13 amps and its 14 and 12 gauge cords at 15, and long runs need thicker wire.

Headlight bulbs are halogen, HID or LED, and a code like H11 names the bulb's fitting; a stock halogen lasts about 500 to 1,000 hours, LEDs far longer.

Headphones differ by fit (earbuds, on-ear, over-ear), by ear cup (open or closed back) and by whether active noise cancelling (ANC) cancels outside sound.

A line laser projects fixed lines for indoor layout, a 360 laser wraps them around the room, and a rotary laser spins one beam for long outdoor distances.

2D, 3D and 4D are makers' own labels for how the rollers move, with no shared standard; compare track type, zero gravity, heat and foot massage instead.

MIG is the easiest process to learn, TIG gives the most control on thin metal, and stick handles rusty metal and wind; size by thickness and duty cycle.

A NAS is a small always-on computer that shares its drives over your network; the number of bays sets your space and how many drive failures it survives.

An unmanaged switch just adds wired ports, a managed switch adds settings and monitoring, and a PoE switch also powers cameras and access points.

Overdrive, distortion and fuzz all clip the guitar signal; overdrive is mildest, fuzz most extreme, and gain pedals go early in a chain, delay and reverb last.

Silicone adds grip, TPU is soft, polycarbonate stays rigid, and "military grade" means a case passed a Defense Department test of 26 drops from 4 feet.

Phone screen protectors come in plastic film (PET or TPU) and tempered glass; 9H is a pencil-scratch grade, and a privacy layer narrows the viewing angle.

Watts say little about how loud a portable speaker plays unless you know how they were measured; an IP rating like IPX7 shows its water resistance.

PSI is how hard the water hits and GPM is how much water flows each minute; multiply the two and you get cleaning units, a quick way to compare machines.

A single DIN car stereo has a 180 by 50 mm face and a double DIN is twice as tall at 180 by 100.3 mm; your dash opening and a fit guide tell you which fits.

Violin sizes run from 1/16 for small children to 4/4 for adults; pick one by measuring the outstretched arm from the neck to the middle of the palm.

Box ranges of 16 to 35 miles assume clear line of sight; FRS radios need no license and cap at 2 watts, while GMRS needs an FCC license and allows more.

Full-frame, APS-C, Micro Four Thirds and 1-inch name the size of the chip that records the image; a bigger sensor gathers more light from the same scene.

One maker's rule of thumb puts viewing distance at about 1.2 times the screen size, so a 65-inch TV suits a seat about 78 inches from the screen.