Link:
https://www.specialized.com/us/en/sa...ready/p/130002
My own pics:
https://imgur.com/a/A5N3I
size: diameter and width, bonus points for actual measurements
42mm. IRL, on Pacenti SL25 rims, inflated they measure exactly that. These are a fair bit smaller in diameter (circumference) than say Panaracer GravelKing SK 43mm. AAMOF, IME they take a full cassette-gear higher ratio to attain the same speeds.
tread pattern: slick, semi-slick with some texture, small knobs for dry conditions, deeper knobs for soft or damp conditions, etc
Kind of a semi-slick. Refer to the pics above. Like the name and pics show, these are a sawtooth pattern of angles from shoulder-to-shoulder. NOTE tread is directional. Great for dry and hardpack. Note, being semi-slick they won't spit gravel like GKs...but they will spray water when wet--either have fenders or be prepared to get rooster-tail up your backside.
construction: tpi, flat protection, tubeless ready, etc
A) 120TPI
B) These are tubeless (Spec calls it "2Bliss" probably to be annoying), and they snap right in easily.
C) These are more a touring tire cable of offroading. They're also a thicker tread and 100grams heavier per tire than say the GravelKing SK 43mm.
performance on pavement
These are beastly tires to use for pavement, unless you're bagged touring/commuting. Otherwise there's little need for a 42mm tire on pavement unless you're commuting through a cratered moonscape of pavement. Being big and heavy, they're slow to accelerate, like all tires this size and weight class. IMHO, unless you're touring or commuting (or mixing touring/commuting/gravel) the 42mm are overkill and the 38mm would be a better choice....although at lower pressure-terrible city streets are nowhere near as bad with a fat tire like this
performance on firm and smooth gravel
Hardpack and smooth, they're great. NOTE the Specialized posted pressures 50-80PSI (for 700x42) are either an outright error--or are idiocy. There's no need to ride a 42mm tire at even 50-PSI unless you're bagged touring with a crapload of camping gear. For solo gravel grinding 30-40PSI produces a nice ride. They have enough bite to go, but not so much as to slow you down with excess traction....sure they're slow to accelerate, but once going they roll nicely and hold momentum well.
performance on deep or soft gravel
These tires simply aren't built for these conditions. For flat courses, so long as you have momentum and control your line, you can make do. But if you stand and power or are climbing in pea gravel, you're going to spin your wheel until you run out of momentum.
durability
I haven't yet even punctured these....despite bagged commuting through broken glass on the MUT. The extra weight does seem to pay dividends in puncture resistance (compared to GK SKs or Vittoria Terreno Dry). Less aggressive tread wears less on pavement as well (I'm looking at you GK SK).
ride
If you ignore Specialized's recommended pressure range...they ride great in either urban jungle or bad roads or MMRs. If you use the recommended pressures, expect to need to see your dentist for your missing teeth.
For people doing hardpack/dry riding or mixing commuting/touring/hardpack-offroading....a great affordable tire at $40 each they a steal IMHO for that use. Any comparable touring/off-roading tire is going to cost 25%+ more each.