Reg and Large on 2.5 plug.

Reg- is 136mm/5.3" long. The head is smooth rounded and 15mm/0.5" at tip and tapers out to 28mm/1" at widest part. The shaft is ribbed 23mm/0.9" and has 1 bulbous rib near the base that is 29mm/1.1" same as the base. On a 2.5 plug.

L-is 151mm/5.9" long. The head is smooth rounded and 34mm/1.3" at widest part and 31mm/1.2" long. It tapers down to 29mm/1" diameter shaft of 119mm/4.7" long. On a 2.5 plug.