Google Crosman Ratcatcher Gunslip and you'll see what I use for my BSA Ultra PCP and its fitted moderator. Bonus is that it doesn't look like a gunslip. But it possibly might have the logo "THE RATBAG" on it. Price is around the eighteen to fifteen quid area. I've seen them listed for Ronnie Sunshines, a place in Kent, Sheffield, eBay.