Clip of mountaineer's nurse hiding a receptacle for rubbish (9)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

CARER (nurse), containing A BIN (a receptacle for rubbish). Reminds me of a slightly pompous headmaster who always told us “deposit your refuse in the receptacle provided”. Metal loop with a spring clip, used by climbers to attach equipment to a rope or harness.