Microshift SL-A11 11 Speed Thumb Shifters - Pair

I recommend this product

Easy to install. Quality feeling. Nice to operate once on the bike.

I recommend this product

These work flawlessly, easy to fit and to operate. Can't fault them. Very pleased

I recommend this product

As the description says, sometimes simple things are better! There's nothing complicated about them, they just work. Beautifully. Cable replacement is so easy you could probably do it in sub-zero temperatures without even taking your gloves off... Indexing is a nice reassuring click, and can be tightened or loosened to preference.
For those of us old enough to remember such things, they're essentially redesigned "SIS" shifters from the early 1990s, reconfigured to work with Shimano 11-speed road groupsets - which does make the price feel a tiny bit steep, but they are very well made!
I'm running mine with a GRX rear mech and it works flawlessly. Front shifter is micro-indexed, so like a friction shifter but with a bit more stability, and works with pretty much anything.
The only caution is that they don't always sit well with hydraulic brake levers - particularly Hope - so some compromise of ergonomics may be necessary when positioning them.