I have a similar camper (5th wheel with 2 main slides) while I had 3 30 amp blade fuses in those holders. Two green (slides) and one black (landing Gear) all were 30 amps.
I changed them all to 30 amp automatic reset current limiters.
Make SURE you get the LONG LEG ones.
Be careful you do NOT break off any of the segmented legs!
Pop out the old fuses and CAREFULLY insert the new ones.
You will not be able to close the caps on the fuse holders with the auto reset limiters in place, so tape them in with electricians tape.
Lou, Laura, & Freya the wonder dog
2008 GMC Sierra 3000HD Crewcab SB Allison Duramax
2019 Flagstaff 8529FLS - Pullrite 3300
HAM CALLSIGN - KC3FFW