These Rings fit the standard 400cc / 500cc / 280cc Theoben bottles as used on most Theoben PCP rifle
Also suitable for:
BSA R10, SUPER 10 And S10
Daystate Air Ranger and Airwolf
Logun & Edgar Brothers S16 Models
These are the uprated hardness seals that were provided by Theoben before they ceased trading.
Not the standard rated O Rings.