hi i'm tim welcome to watchbox and thanks for logging on if you love this watch email me tmaso thewatchbox.com your purchase and pricing email question line for buying this or any watch you see on any watch box platform reach out to me directly email tmaso thewatchbox.com for pricing today we are discussing a 2021 evolution of watch originally launched in precious metal for 2015. this is the patek philippe 5905-1a-001 it is a flyback chronograph and it is an annual calendar green dial sunburst full bracelet all steel construction this is probably what the 5905 should have been from the beginning now the watch is 42 millimeters in diameter by 14.3 millimeters thick if we're counting just the case from lug tip to lug tip it is 50.5 millimeters if you measure the end link to end length the total distance across the wrist is 53.5 millimeters and has a broad and modern 22 millimeter spacing between the lugs throw it on the wrist my wrist is 16 centimeters in circumference and it's a large watch it is effectively an evolution of the 5960. that's what the 5905 was simplified and larger it's an evolution of the 5960 but the watch has a lot more wrist presence especially with the end links of the bracelet this watch has a huge span across the wrist so i recommend it for wrists of 15 centimeters circumference or larger any smaller you're going to want to look at a 5960. it is however thin enough to fit underneath the cuff with the concave bezel and the sloped case blank you should be good to go with dress sleeves the bracelet is very similar to what you'll find on an aquanaut we have a conforming end link to better mate with the edge of the case creating a more integrated look we have polished outer links that are also polished on their outer face we have satinated center links that are rolled internally and then you can see the outer links have a little bit of tumble home you can see that they roll off to the side that's another feature of the three link aquanaut style bracelet this is very similar to the aquanaut bracelet you can see removable links are fixed with pins and sleeves it's a robust and secure system but you will need a block and a punch if you want to size this at home we have a double folding clasp you can see externally there's a kalatrov across twin trigger release polished internally you can see components of the cali travel cross here you must press both triggers to release this is truly a sports watch bracelet and clasp very robust you can also see that they're big enough gaps between the links that won't pinch skin pull hair or trap wrist heat taking a look at the case patek uses some clever measures to visually slim the watch starting with a concave bezel we add very fine tapered and elongated lug profiles and scalloped case flanks with a pronounced concave profile everything is mirror finished see there are three adjusters on the flank of the watch that's for adjusting the calendar and then there's a little hole at the bottom of the chronograph minutes register that will turn blue during the nighttime hours when you should not use these so while that acts as an ampm indicator it's really there to let you know not to use these pusher adjusters to adjust the calendar during the blue aperture hours of the day the dial features a 60 minute chronograph register it has the am pm indicator a flyback chronograph that you can reset and restart without first stopping it features a american style day-date month aperture annual calendar patek invented this technology in 1996 they were the first with the annual calendar gives you most of what a perpetual calendar affords but without the maintenance diva issues that you have to deal with down the line it's much more robust and cheaper to service you adjust it once a year annually during the jump from february to march new for 2021 the green metallic sunburst dial voguish yes but also with a lasting beauty it's best described as an olive green metallic we have a sector style dial and you can see the sector is composed entirely of metal elements we have polished chapter rings that run concentrically and then they are sectored by the perpendicular overlap of faceted applique white gold hour indices we also have a polished chaptering for the small seconds or i should say the small minutes which is sunken into the dial so you've got your chronograph minutes up to 60. i actually like that because a lot of times with a 30 minute chronograph register i can lose track of which half the hour i'm in with 60 minutes it's a lot more intuitive all of the indices the frame for the date they are white gold along with the hands center so they will not oxidize or tarnish over time let's do a quick loom shot and you can see the watch has plenty of loom now it's important to note that this watch is a rather sporty timepiece it's one shortcoming as a sports watch is the 30 meter water resistance so it's steel full bracelet well loomed and automatic but this is a sports watch for enjoyment high and dry turning it all over you can see a version of caliber 285 20 originally designed for the 5960 and the nautilus chronograph you can see it is a column wheel chronograph i talked a little bit about the flyback function you can use it as a zero reset because this is a column wheel which means it's crisp but it's also a vertical clutch which means two things one the chronograph engages with zero jump or stagger there is no play in a vertical clutch second with a vertical clutch you can leave the chronograph running with no hazard to the movement so if you want to have your hours your minutes and your seconds at center just ignore the chrono minutes register treat this as your seconds hand and though the watch does not have a hacking seconds function once you set the time precisely instantaneously zero reset the seconds hand and it acts like a zero reset hacking seconds so you can synchronize to your reference time and have that live dial remember when this chrono's off nothing moves on the dial a lot of people like to run the chrono full time on these so you also have a number of features the patex seal the anti-magnetic silicon hairspring the six position adjustment the gyromax style balance that add up to a patek philippe accuracy guarantee of minus three plus two seconds per day so this actually has an attestation from the factory that will meet a certain standard of precision it pivots on 37 joules it beats way at four hertz or eight beats per second and it is extensively hand finished it uses efficient unidirectional winding and ceramic rotor bearings in tandem to energize its 55-hour automatically wound power reserve reach out to team also at thewatchbox.com for purchase and pricing details