I bought an even smaller unit, also from Walmart, no product number is listed on box but it's the same maker; Campbell Hausfeld. Has a built in PSI meter and dimensions are approx. 6" x 5" x 3" boxed.
Good idea as to tearing off the case and making it smaller - could probably "hard wire" it to a bike and hide the guts in the "bike manual" box under the sidecover.
Good link, forevrtxan, thanks.
by the way, cost also was $10