Not legal in California or Colorado
These are 20 round magazines with a simple (2.4" wood insert) mag block. Since the magazine floor plate is removable, and the mag block is not permanently fixed, the magazine is readily convertible to 20 rounds within seconds without any tools.
California, COR Title 11, Div 5, Ch 39, Art 5, 5491, (b), 1.A, requires a mag block limiting the capacity to 10 rounds and the magazine floorplate to be permanently altered (non-removable) using epoxy.
Colorado, CRS 18-12-301, (2), (b), (1) requires the magazine capacity be limited to 15 rounds and permanently altered.
I permanently altered the ProMag FNH 01 magazines by driving pins through the mag block, trapping the mag block at the bottom of the magazine spring, then using enough 24-hour epoxy to glue the mag block, bottom of the magazine spring, and floorplate into one permanently altered, non-removable piece. I made a shorter mag block to limit the capacity to 15 rounds IAW Colorado law and permanently altered the magazine as previously described.
When I purchased these magazines, I incorrectly assumed they would conform to State Laws concerning capacity and not readily converted. The price is excellent, the quality is very good, but extra work may be required to possess these magazines legally in some states.
Verified purchase: YesCondition: New