I heard that B&F don't sell the collar on it's own now for this reason unless you've previously bought a box from them. Could well be wrong though,,so don't take my word for it...
Sorry to butt in but personally i'd regard a lurcher that wasn't safe with terriers in the same light as 1 that wasn't safe with livestock and have it pts, imo 1 good terrier is worth more than any amount of good lurchers.....