16mm spacer to secure your HAT on the Raspberry-Pi
Here Black Plated M/F Brass 16mm Standoffs (tall standoffs). They are particular useful with some Pi accessories and some products like the PiTFT because they have extra tall headers attached to the board/hat.
Such extra tall standoff will properly secured while also keeping the two boards separated. The standoffs can also be screwed to each other and also screwed on the 11mm standoffs (the 1mm standoff are used with the normal Raspberry-Pi HATs).
For each order you will get: two standoffs and two hex nuts.