This Dentec Safety Specialists combination cartridge puts an ammonia and methylamine bed behind a P100 filter. Comes as a box of 60. Dentec lists it as USA made, and their respirator plant is in Lenexa, Kansas.
NIOSH approves whole respirators, not loose parts. This one is covered under NIOSH 84A-0951 in the facepiece and setup that approval names. Put it on something the label does not list and the respirator you are wearing is no longer approved. The protection factor belongs to the complete respirator too, not to this part by itself.
Anywhere respirators are required, OSHA 1910.134 wants a written program behind them: medical evaluation, fit testing, training. Gas and vapor cartridges then need one of two things, an end-of-service-life indicator NIOSH certified for your contaminant, or a change schedule worked out from real service-life data and written into the program. Smell and taste do not count either way. The rest of the line is under respirator cartridges and filters.