Best watch strap retaining pins has 1 long cylinder with spring loaded pins at each end that fit into holes in watch lugs. Watch pins cylinder should be long enough to just fit between watch lugs. Extra space that is taken up by pins extending beyond the cylinder or by having telescopic spring bars let the pins slide out releasing watch from one strap end. Manufactures must like strap pins with telescopic spring bars because they are easier and quicker to install and can result in lost watch that needs replaced. I always have my strap pins replaced with tight fitting pins. Exception is metal watch bands with tight fitting ends that prevent band ends sliding on strap pins.
Watch band pins shown at the link:
I use Double shoulder spring bars not Double flange spring bars to have almost zero clearance between cylinder and lugs.
http://www.esslinger.com/watchbandpi...strations.aspx