Leather case with a brass cartouche. The case is lined with a burgundy silk on the lid and purple velvet on the base.
The unit is armed with the bar on the top. The depth of the final cut is controlled with the screw mechanism at the back, and the release mechanism is a standard levered bar release.
Unmarked c.1815-1830 spring lancet, country of origin is England. A very similar item is illustrated in Davis and Appel (pg 102 figure 122). That item is marked "Weiss improved bleeding instrument", 33 Strand London. This maker and address would put the unit sometime after 1811.
Back of the unit showing the depth gauge mechanism.