Sports & Outdoors Specs Explained

Compression rates how firm a golf ball is; low suits slower swings, high suits faster ones, and the cover and layers decide spin and feel near the green.

A home golf simulator room is usually about 10 feet high, 10 to 14 feet wide and 15 to 20 feet deep; radar launch monitors need more depth than camera units.

New US life jacket labels rate flotation in newtons, Level 50 to 275, not Type I to V; most sold are Level 70, and the label's weight and chest range set size.

Set a trekking pole so your elbow bends at a right angle with the tip by your foot; Leki's starting point is your height in centimeters times 0.68.

Fixed dumbbells are one weight each and ready to grab; adjustable dumbbells change weight with a dial or plates and replace a rack in the space of one pair.

Choose bat length by age, height and weight, then the drop (length minus weight) and the certification stamp your league requires, such as USA, USSSA or BBCOR.

Batting gloves are sized by hand length from palm base to middle fingertip, fielding gloves by inches for age and position, and boxing gloves by hand size.

Bike helmets are sized by head circumference in centimeters, US bike helmets carry a CPSC label, and MIPS is a low-friction layer for rotational impacts.

Adult bike frames are sized XS to XL by rider height, about 5 feet to 6 feet 4 inches on a typical chart; mountain bikes and hybrids differ in tires and fit.

The mmHg number on compression socks is the squeeze in millimeters of mercury; 15-20 is lighter and 20-30 firmer, and a good pair feels tight at the ankle.

A hockey stick's flex number tells you how stiff it is; Bauer suggests starting a bit under half your body weight in pounds, and a cut stick gets stiffer.

Kayak paddle length depends on boat width and your height, from about 200 cm for a narrow boat and short paddler to 250 cm for a wide boat and tall paddler.

An ISO sleeping bag rating gives a comfort temperature and a lower limit; cold sleepers go by comfort, warm sleepers by the limit, both with a margin.

Snowboard bindings are sized to your boot, so pick the binding from the maker's boot chart, then choose straps, a step-on system or a rear-entry design.

Soccer balls run from size 1 to 5 and basketballs from size 3 to 7; the right one depends on the player's age, and basketball size also on the league.

The number on a spinning reel, such as 2500 or 4000, is a size class; higher means a bigger spool, more line and drag and bigger fish, though brands differ.

Swim goggles differ by shape (racing, comfort, open water, mask) and lens (clear, mirrored, tinted, polarized); a good fit gives suction without the strap.

Compare continuous horsepower (CHP), not peak horsepower; walkers need about 2.0 CHP, joggers about 2.5 and regular runners 3.0 or more.

Common water bottles hold 12 to 48 fluid ounces, and a 32 oz bottle is about 946 mL; the right size depends on how often you can refill it during the day.

A 3/2 wetsuit is 3 mm thick at the torso and 2 mm at the arms and legs; O'Neill suggests a 3/2 or 4/3 for water around 55 to 64°F.

Shorter, wider kayaks feel steadier and turn easily, longer, narrower ones track straight and glide faster, and weight capacity must cover you and your gear.