3M 1110 UF foam ear plugs (corded version of the 3M 1100 ear plugs) are the stiffest of the poly-urethane foam ear plugs. For those who like the feel of UF, but want the stiffness of PVC (which makes insertion easier)
3M Classic Foam Ear Plug 28 SNR - Box of 250
3M™ 1270 - Corded Reusable Earplugs - Safetyware Sdn Bhd
3M E.A.R Soft Yellow Neons Corded Earplugs
3M 1110 Corded Foam Ear Plugs (100 Pack)
3M 311-1252 E-A-R Soft Yellow Neon Blast Corded Earplugs (200 Pr
3M 1100 Ear Plugs
3M EARsoft™ Yellow Neons Uncorded Ear Plugs (SLC80 23dB, Class 4
3M™ Ear Plugs 1100, 30 PR/PK (94-105 dB)
PJD Safety Supplies. 3M 1271 Corded Ear Plugs 25dB - 50 Pairs