They are HYDRAULIC LASH ADJUSTERS for 95-09 Mazda Ford Lincoln Mercury 2.5 and 3.0 engines. Often incorrectly called "lifters", they actually collapse a little when the valve is opened by the cam. Go to Ebay.com and put the item number 281743301736 in the search field and you will find a photo of them, and a guide to the vehicles they fit. 4-cylinder engines have 16, 6-cylinder engines have 24.

They are HYDRAULIC VALVE FOLLOWER UNITS for a double-overhead-cam 4-cylinder 16-valve engine, possibly Mitsubishi. The Units go in holes in the cylinder head near the valves. The cam is above the valve and hydraulic unit, and a CAM FOLLOWER (similar to a rocker arm) goes between the valve and hyd unit. The hyd unit has a spring inside and is fed oil from a passage in the head. This maintains valve clearance.

Reason:
I can't find a matching set of FOLLOWERS for a double-overhead-cam 4-cylinder 16-valve engine. Could you provide a link for an exact match? I need to know precisely what vehicles these go to. Thank you for your help so far.

They are HYDRAULIC LASH ADJUSTERS for 95-09 Mazda Ford Lincoln Mercury 2.5 and 3.0 engines. Often incorrectly called "lifters", they actually collapse a little when the valve is opened by the cam. Go to Ebay.com and put the item number 281743301736 in the search field and you will find a photo of them, and a guide to the vehicles they fit. 4-cylinder engines have 16, 6-cylinder engines have 24.

References:

Other Ebay item numbers: Mitsubishi 3000 91-06: 271184062031. Mitsubishi Chrysler Eagle Jeep: 251864668885. Toyota 82-88: 281745112946. Hummer: 351465585369. Isuzu trooper: 251867581002. GM 4.2 02-09: 300802230569. All different from yours.