Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: 4 1/4" philadelphia cervical collar

The product received on time, however, the item is a mismatch, the front part and the back part is not perfectly match eachother, extremely hard to line up right. The price of cause is much cheaper than the regular local drug store, I wish they should mentioned "irregular" before I have purchased, that make understanding before order. The product still work, but not comfortablely match.