Diy gps speedometer on your hand

I wanted soemthing that display real time speed, and i wanted that i ease readable with big nice display.
My remote also home made dont display speed, so another project begun.
I founde nice little gps speedometer for car that i figured out it would fit on the wrist and make gps wrist watch.
This car gps speedometer powers from usb 5v so i also needed some tiny boost converter and lithium charger to get it powerd from battery, that can also be founde on aliexprees but i used one that i have.
Battery is 300mA lipo used in small rc helicopters and drones.
I have modeled new case that resambles watch and some 3d printing and little soldering my gps speedometer for efoiling was done.
To turn on/off i used reed relay and smal flat magnet that slides into small pocket on the side.
Also, i have put few coats of clear coat over pcb and whole watch body will be filled with 2k silicone, to make it waterproof
heare are the links for gps speedometer

also this magnet cable is needed for charging.{"sku_id"%3A"12000017733952641"}&pdp_npi=2%40dis!HRK!26.65!14.64!!!!!%40210218bf16745136381726209d06b0!12000017733952641!sea&curPageLogUid=8ARSjhqhi7ie.
link for the housing model.{"sku_id"%3A"10000015383353588"}&pdp_npi=2%40dis!HRK!69.25!69.25!!!!!%40212279a216745485973402252d0686!10000015383353588!sea&curPageLogUid=pM8m4ByjgR5v&ad_pvid=202301240023176521476374980400022472389_1&ad_pvid=202301240023176521476374980400022472389_1
Straps are cutted from one of this, that fits in the slots on housing and secured with glue and screwes.